Vessel cannulation device and method of use

ABSTRACT

Devices and methods are provided for automatic vascular access. An automatic vessel cannulation device, mechanical or electronic, has a sensor configured to detect a physiologic parameter of a needle tip, and a blunting device advancing member released in response to the sensor. The sensor may measure pressure or any other physiological parameter. A processor is configured to analyze data sent by the sensor and is pre-set to identify parameters unique to arteries, veins, or other body cavities or organs. A method may include comparing a physiologic parameter with pre-determined parameters to deploy a blunting element if the physiologic parameter is within a range of the pre-determined parameters. An expandable sheath may be included. A device can be provided having a motor controlling the cannulation device orientation to scan tissue with the tip of the needle by moving the cannulation device through the ultrasound transducer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Nos.62/311,249 (filed Mar. 21, 2016) and 62/183,554 (filed Jun. 23, 2015),both of which are hereby incorporated herein by reference in theirentirety.

BACKGROUND

Vascular access is a crucial element of medical therapy in a vastmajority of clinical settings and procedures. This is true in bothelective and in emergent situations. In a specific type of emergency,hemorrhagic shock, there may further be a need to perform aorticocclusion. Both these clinical needs, vascular access and aorticocclusion, are the subject of the current invention.

Vascular Access

A large part of medical interventions, both elective and emergent, areendovascular procedures. These procedures have become very common andcontinue to grow in numbers due to both the increase in cardiovascularpatient absolute numbers and to the trend of shifting from open surgeryto endovascular surgery.

Once vascular access is secured, delivery of treatment is quick andeasy, be it the administration of fluids, analgesics, sedativemedications, vasopressors, inotropics, percutaneous endovasculartrans-catheter treatments or other interventions. Patient monitoring isalso aided by central vascular access, as it enables direct arterial orvenous pressure measurements and blood sampling.

Vascular Access in Elective Situations

Although extremely common, the ways to establish vascular access remainvery basic and are often inadequate. This is especially unfortunate inelective settings, as it is the older and sicker individuals who usuallyhave more “difficult blood vessels”, and must frequently endureadditional suffering caused by painful repeated attempts at blood vesselcannulation, even when performed by experienced personnel.

Vascular Access in Emergency Situations

In emergency situations, the importance of vascular access is increased,as stabilization of patients often requires administration of fluids orblood and medications. However, the emergency setting also increases theobstacles to successful blood vessel cannulation. Possible impedimentsinclude environmental factors such as darkness (night), cold and wetweather, unstable surroundings (wind, waves, bumpy vehicle or aircraft),patient factors such as shock which may cause collapse of veins and animpalpable arterial pulse, burns, or movements due to shivering orconvulsions, care provider factors such as stress caused by the need todeliver therapy urgently in a dying patient, additional patients,imminent danger from warfare or natural hazards, or lack of expertise,and finally equipment factors such as the absence of expensiveultrasound guidance. A venous cut down may be performed using simpletools by an experienced physician, but this too takes time and requirescertain expertise, making it impractical in many cases.

In performing an endovascular procedure, access into the vasculaturemust be established and maintained for the duration of the procedure.This is most commonly done by placing an introducer sheath in the bloodvessel to enable passage of the interventional instruments in and outwithout losing the entry point or causing damage to the vessel.

Placement of an endovascular sheath is usually performed using themodified Seldinger technique. This entails puncture of the vessel with aneedle, passage of a guidewire through the needle, removal of theneedle, incision of the skin, placement of a sheath with a dilator in itover the guidewire, removal of the guidewire and dilator.

The Seldinger technique, although useful, suffers from severaldrawbacks. First, it requires significant experience in order to besuccessfully performed, especially when circumstances are suboptimalsuch as in emergency and trauma situations. As it is mainly used forplacement of large bore catheters, which are less common than regularsmall-medium bore venous catheters, the exposure to it (and hence theprocedure practice) is less than that of over the needle venous catheterplacement. Second, there are several points during the procedure whichmay lead to its failure.

One such point is after entry of the needle into the blood vessel, whichis evident by the flow of blood out of the needle. At this point, thephysician must thread a guidewire into the needle. Holding the needleabsolutely still, while bringing the guidewire and threading it with theother hand requires a certain level of coordination, which not allphysicians possess. Even the slightest movement of the needle at thisstage might cause it to move forward and exit the artery through itsposterior wall, or withdraw out of the lumen through the anterior wallof the artery. This will prevent the guidewire from entering the lumenand will require an additional puncture attempt. Additionally, thismight cause blood to leak around the vessel causing an internalhematoma, which might compress the vessel and make repeat cannulationmore difficult. Worse yet, unintended movement of the needle might placeit within one of the arterial walls, and attempted insertion of theguidewire can then damage the arterial wall, possibly leading to largehematomas or other complications.

Another sensitive point in the procedure is after the guidewireinsertion and needle removal. The physician must now thread theguidewire edge into the dilator, which has a very small aperture thesize of the guidewire, while at the same time compressing the puncturesite to prevent hematoma and make sure the guidewire is not pulled out.Exit of the guidewire from the artery at this stage will cause thesheath to be placed into tissues instead of into the artery, whichbesides tissue damage usually causes the guidewire to bend,necessitating its replacement.

Additional drawbacks of the Seldinger technique are related to the useof a long guidewire, which carries with it an increased risk ofcontamination of its proximal end, as well as a danger of splashingblood on the physician. Also, during the time between needle entry intothe vessel and until the guidewire is inserted into it, either profusebleeding or entry of air into the circulation might occur, depending onwhether pressure within the vessel is higher or lower than ambientpressure.

In contrast to the above, regular small to medium bore venous cannulasare usually placed using the “over-the-needle” technique. With thistechnique, the cannula, which has an inner diameter (“ID”) matched tothe outer diameter (“OD”) of the needle, is inserted into the arterytogether with the needle. When blood is observed in a “flash” chamberconnected to the needle lumen, the needle is held in place and thecannula is manually advanced and slid over the needle into the vessel.Not only is this technique technically simpler than the Seldingertechnique, it is also more commonly used, and there is a greaterpossibility of exposure to it for training, so the learning curve issignificantly shorter and competence in it is easier to maintain.

In the “over-the-needle” method, the cannula must have an ID matched tothe OD of the needle, in order for it to enter the vessel with theneedle. Therefore, the diameters of cannulas inserted using thistechnique are limited to the outer diameters of needles that can be usedfor these purposes, which are usually 21 G-18 G (0.8 mm-1.3 mm).Endovascular procedures often require insertion of instruments havingODs of 8 fr-14 fr (2 mm-4.6 mm) or more.

Since the “over-the-needle” technique is not adequate for placing largebore catheters or sheaths, the Seldinger technique is used in thesecases, which as mentioned, include most endovascular interventions.

The WAND, manufactured by Access Scientific of San Diego, Calif., is adevice intended to provide a solution for the above drawbacks of theSeldinger technique. This device includes a needle, guidewire, dilator,and sheath in an all-in-one assembly, which is intended for easier andsafer over-the-wire sheath insertion. Use of the WAND requires manualadvancement of both the guidewire and the sheath by the operator. TheWAND mainly addresses safety issues such as needle-stick injury and airembolism, but the technique is still rather complicated and requiressignificant training.

Expandable sheaths were described in the art in various contexts, mainlyfor retrieval of large devices such as heart valve delivery systems,aortic balloon catheters etc. usually having self-expanding and balloonexpandable components. Such solutions are cumbersome and expensive andare not appropriate for direct over-the-needle vascular access.

Another drawback of existing sheaths related to their having a fixeddiameter, is that the arterial puncture site remains dilated to themaximum size for the whole duration of the procedure. The duration ofpuncture site dilation is one of the factors affecting the chances ofits closure. With the current invention, the artery would only beexposed to maximal dilation when the largest instruments are used, whileduring the rest of the procedure, it will be only slightly dilated. Thiswill increase the successful closure rates and reduce puncture sitecomplication rates.

It is therefore an aspect of the current invention to provide a simple,safe, easy to use, and low cost solution for establishing vascularaccess.

BRIEF SUMMARY OF THE INVENTION

In one aspect of the invention, improved devices and methods areprovided for vascular access, including various mechanical andelectronic vessel cannulation devices, some of which comprise bothdisposable and reusable parts.

In one aspect of the invention, new blunting devices are provided forvessel cannulation needles, as well as improved expandable sheaths foruse alone or in combination with the above devices. The blunting devicesin accordance with the present invention may be advanced either insideor outside a needle to cover the tip of the needle, thus preventing orreducing the chance of the needle puncturing through the blood vessels.

In one aspect of the invention, a cannulation device is provided,whether mechanical or electronic, that may be capable of (1) advancing aguidewire through a needle, (2) advancing a sheath over a needle, (3)both of the above, together or in succession, (4) deploying other“blunting” elements; and (5) providing an indication to the user, or toan automatic system preforming the cannulation.

An embodiment of the invention is an automatic vessel cannulation deviceincluding housing, a lumen, a needle, a sensor, and a blunting deviceadvancing member. The housing may have a distal end with a distal tipand a proximal end. The lumen may pass through the distal end and theproximal end. The needle may be at the distal tip of the housing,wherein the needle having a needle tip. The sensor may be operablycoupled to the lumen, wherein the sensor may be configured to detect aphysiologic parameter at the needle tip. The blunting device advancingmember may be configured to advance a blunting device through the lumen,wherein the blunting device advancing member may be operably coupled tothe sensor. The blunting device advancing member may be configured toautomatically advance the blunting device when the sensor detects thatthe physiologic parameter within a pre-determined range. The sensor maybe selected from the group consisting of pressure sensors, temperaturesensors, conductivity sensors, flow sensors, ultrasound sensors, pHsensors, and optical sensors.

In another embodiment, the vessel cannulation device may further includea trigger mechanism. The trigger mechanism may include a sear and alever, wherein the trigger mechanism may be configured to release theblunting device advancing member when the sensor detects that thephysiologic parameter is within the pre-determined range. The lever mayinclude a hinge located at the distal end of the device, a lever toothat the proximal end, and a lever base between the hinge and the levertooth. The sear may be located at the proximal end of the lever andengages the lever tooth. The lever may include a hinge at the proximalend of the device, a lever base at the distal end of the device, and alever tooth between the hinge and the lever base; wherein the leveroperably coupled to and moveable by the sensor. The sear may be locatedbetween the proximal end and the distal end of the lever and engages thelever tooth. The distance from the center of the sensor to the hinge istwice the distance from the lever tooth to the hinge.

In some embodiments, the sensor may be a membrane. In some embodiments,the sensor is an electronic sensor. In some embodiments, the sensor maycomprise multiple sensors.

In another embodiment, the vessel cannulation device may further includean adjustment mechanism configured to be in contact with the triggermechanism, wherein the adjustment mechanism adjusts force applied on thelever.

In another embodiment, the vessel cannulation device may further includea CPU. The CPU may be in electrical communication with the sensor andmay be configured to execute instructions, wherein when executed, theCPU may be configured to compare the physiologic parameter from theneedle tip with predetermined values to determine whether the needle tiphas punctured a blood vessel.

In another embodiment, the vessel cannulation device may further includea solenoid in communication with the CPU and connected to the triggermechanism. The solenoid may activate the trigger mechanism when it isdetermined that the physiologic parameter from the needle tip matchesthe predetermined parameter of the blood vessel. The solenoid may beconfigured to activate outside of a predetermined time window, whereinthe predetermined time window for a vein is between 0.05-0.3 seconds,and the predetermined time window for an artery the window is between0-0.05 seconds.

In another embodiment, the vessel cannulation device may further includean input device for choosing a blood vessel type, wherein the bloodvessel type is an artery or a vein. The artery has a predeterminedparameter of lower threshold (LTH) of 20 mmHg, upper threshold (UTH) of300 mmHg, and range of pressure change rate of +/−400 mmHg/sec. The veinhas a predetermined parameter of lower threshold (LTH) of 5 mmHg, upperthreshold (UTH) of 20 mmHg, and range of pressure change rate of +/−100mmHg/sec.

In another embodiment, the blunting device advancing member may becoaxial with a large spring. The blunting device and the blunting deviceadvancing member may be covered by a sterile cover within the device.

In another embodiment, the vessel cannulation device may further includea blunting element configured to expand to cover the needle tip whendeployed. The blunting element may be stent-like. The blunting elementmay be selected from the group consisting of an external sheath, aninternal sheath, a sandwich sheath, a tip covering sheath, and a tipcompleting sheath. The internal sheath may be a guidewire with anuncoiled segment or a coiling guidewire. The internal sheath may bedeployed by pushing the internal sheath towards the needle tip with acannulation device. The internal sheath may be configured to bepositioned within the needle in its crimped state without substantiallyblocking the needle lumen.

In another embodiment, the vessel cannulation device may further includea fluid passageway coupling the sensor to the lumen; and wherein thefluid passageway is substantially straight and has an internal diameterof 0.5 mm-2.5 mm, and a length no longer than 4 cm.

In another embodiment, the vessel cannulation device may further includean impact absorbing element for dampening noise and recoil duringadvancement of the blunting device.

In another embodiment, the vessel cannulation device may further includea cocking mechanism configured to bring the device to a cocked state.

In another embodiment, the vessel cannulation device may further includea cover comprising a safety latch slot and a safety latch.

In another embodiment, the vessel cannulation device may further includea disposable part and of a reusable part.

In another embodiment, the vessel cannulation device may further includea barrier allowing sensing of pressure to be performed while keeping thesensor sterile, and wherein the sensor is reusable.

In another embodiment, the vessel cannulation device may further includea guidance element. The guidance element may be selected from a groupconsisting of a linear mechanical guide or a rotary mechanical guide.The guidance element may include imaging means. The imaging means mayconsist of an ultrasound transducer. The ultrasound transducer may belocated proximal to the needle tip, and wherein the needle can slidethrough the transducer. The ultrasound transducer may allow replacementor removal of the needle.

In another embodiment, the vessel cannulation device may further includea mat including: a position sensors, a processor, and an indicator. Theprocessor may be configured to gather ultrasound signals received by theultrasound transducer simultaneously with the position information fromthe position sensors. The processor may activate the indicator to signalwhen the cannulation device is pointed at a blood vessel.

An embodiment of the invention is an automatic system for vesselcannulation including: a mat, a motor, a processor, a vessel cannulationdevice, and an ultrasound transducer. The mat may have position sensorsand a sliding strip. The motor may control a movement of the slidingstrip. The processor may be in electronic communication with the mat.The vessel cannulation device as described above, which may be slideablypositioned within a housing and pivotally connected to the mat throughthe sliding strips. The vessel cannulation device includes a needle. Theultrasound transducer may be slideably positioned over the tip of theneedle of the vessel cannulation device. The motor may control anorientation of the cannulation device through the sliding strip. Thesystem may scan tissue with the tip of the needle by moving thecannulation device through the ultrasound transducer. The processor maydetect a target vessel and advance the vessel cannulation device towardsthe target vessel until the vessel cannulation device deploys theguidewire within the vessel or until a maximum depth is reached.

An embodiment of the invention is an expandable sheath system including:an expandable outer layer sheath and an inner rigid layer. Theexpandable outer layer sheath may include longitudinal beams and a step.The inner rigid layer may comprise a bulb and a shoulder which engageswith a step of the outer layer sheath. The inner rigid layer sheath maybe configured to fit over a needle shaft; and after removal of theneedle, the bulb may be collapsed and the inner rigid layer sheath maybe removed from the outer layer sheath, while leaving the outer layersheath in its position within a vessel. The inner rigid layer may be anintegral part of the needle.

An embodiment of the invention is an expandable sheath configured to beinserted into a patient's body over a needle. The expandable sheath maycomprise rigid longitudinal beams and an expandable elastic layer. Thelongitudinal beams may be bridged by connections creating a spiralpattern along and around the sheath. The expandable sheath may comprisean external sheath slideably positioned over the expandable outer layersheath.

The external sheath may include a handle and a support elementconnecting to the expandable outer layer sheath. The external sheath maybe tearable. The expandable sheath may further include a rigid largediameter sheath that is configured to be inserted into the expandableouter layer sheath, to maintain and expand the expandable outer layersheath.

An embodiment of the invention is an expandable sheath configured to beinserted into a patient's body over a needle, including: a sheath havinga single substantially inelastic layer and an inner diameter. In acrimped state, the sheath inner diameter may be in a tight fit with aneedle. In the expanded state, the sheath inner diameter may be at leastdouble the sheath inner diameter in the crimped state. The inelasticlayer may have multiple micro-corrugations. The inelastic layer may havebetween 2 and 6 large corrugations folded around the sheath. Theexpandable sheath may have one corrugation, and wherein this corrugationis folded around the sheath at least once. The expandable sheath mayinclude: the distal end of the inelastic layer comprises a part that isperpendicular to the longitudinal axis of the sheath, and a part that isat an angle relative to the longitudinal axis of the sheath, configuredto create a smooth distal taper for the sheath in its crimped state. Theexpandable sheath may further include a hub configured to overlap with aneedle hub.

An embodiment of the invention is a method of using a vessel cannulationsystem including: calibrating the system by selecting a target vesseltype having pre-determined parameters; penetrating a body with a needleto detect a physiologic parameter, wherein the needle is in electroniccommunication with the system; comparing the physiologic parameter withthe pre-determined parameters; and deploying a blunting element into thetarget vessel if the physiologic parameter is within a range of thepre-determined parameters. The method may further include pushingforward the inner sheath from an inner lumen of the needle towards adistal tip of the needle. The deploying step further comprisesactivating a solenoid to trigger a trigger mechanism to advance theblunting element. The method may further include placing a mechanicalguide on the body with a central marking above an estimated location ofthe target vessel.

In some embodiments, the blunting element may be configured to bepositioned within the needle in its crimped state without substantiallyblocking the inner lumen, and to cover a distal tip when the bluntingelement is deployed. The blunting element may be selected from the groupconsisting of an external sheath, an internal sheath, a sandwich sheath,a tip covering sheath, and a tip completing sheath. The blunting elementmay be pulled back following deployment to cover the needle tip.

In some embodiments, the mechanical guide may be an ultrasoundtransducer.

In some embodiments, the calibrating step may comprise choosing a targetvessel type, wherein the target vessel type is an artery or a vein. Theartery may have a pre-determined parameter of lower threshold (LTH) of20 mmHg, upper threshold (UTH) of 300 mmHg, and range of pressure changerate of +/−400 mmHg/sec. The vein may have a pre-determined parameter oflower threshold (LTH) of 5 mmHg, upper threshold (UTH) of 20 mmHg, andrange of pressure change rate of +/−100 mmHg/sec.

In some embodiments, the penetrating step may include using sensors todetect the physiologic parameter at a needle tip.

In some embodiments, the method may further include inserting a centralcatheter into the target vessel through the blunting element, whereinthe blunting element is an expandable sheath.

In some embodiments, the method may further inserting a peripheral IVcatheter into the target vessel through the blunting element, whereinthe blunting element is an expandable sheath.

In some embodiments, the method may further drawing blood samplingthrough the blunting element.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe invention, will be better understood when read in conjunction withthe appended figures. For the purpose of illustrating the invention, thefigures demonstrate embodiments of the present invention. It should beunderstood, however, that the invention is not limited to the precisearrangements, examples, and instrumentalities shown.

FIG. 1A is a longitudinal cross section of a mechanical cannulationdevice in accordance with embodiments of the invention, which depictsthe guidewire advancement mechanism in a cocked position.

FIG. 1A′ is a longitudinal cross section of a mechanical cannulationdevice in accordance with embodiments of the invention, which depictsthe guidewire advancement mechanism in a deployed position.

FIG. 1B is a top view of a mechanical cannulation device in accordancewith embodiments of the invention.

FIG. 1C is a top view of membrane 60 of a mechanical cannulation devicein accordance with embodiments of the invention.

FIG. 1D is a longitudinal mid-section of a membrane of a mechanicalcannulation device in accordance with embodiments of the invention.

FIG. 1E is a cross section of a membrane of a mechanical cannulationdevice in accordance with embodiments of the invention.

FIG. 2A is a longitudinal cross section of a mechanical cannulationdevice in accordance with one embodiment of the invention.

FIG. 2B is a longitudinal cross section of a mechanical cannulationdevice in accordance with another embodiment of the invention.

FIG. 2C is a longitudinal cross section of a mechanical cannulationdevice in accordance with an alternate embodiment of the invention.

FIG. 2D is a longitudinal cross section of a mechanical cannulationdevice in accordance with yet another alternate embodiment of theinvention.

FIG. 2Di is a perspective view of cannulation device 1000.

FIG. 2E is a longitudinal cross section of a mechanical cannulationdevice in accordance with yet another alternate embodiment of theinvention.

FIG. 2F is a top view of the device in FIG. 2E in accordance with analternate embodiment of the invention.

FIG. 3A is a schematic longitudinal section of an electronic vesselcannulation device in accordance with embodiments of the invention.

FIG. 3B is a schematic longitudinal section of a trigger mechanism inaccordance with embodiments of the invention.

FIG. 4 is a schematic longitudinal section of an electronic vesselcannulation device in accordance with embodiments of the invention.

FIG. 5A is an exemplary flowchart that may be implemented using thedevices of the invention in accordance with certain embodiments of theinvention.

FIG. 5B is a graph produced using a device in accordance withembodiments of the invention.

FIG. 5C is a theoretical graph depicting possible multiple physiologicparameter measurement values during puncture through a patient's tissuesand blood vessels, which may be used in accordance with embodiments ofthe invention.

FIG. 5D is a simplified theoretical graph depicting various possiblepressure measurement contours.

FIGS. 6A-6D show a stent like “tip covering” blunting element inaccordance with an embodiment of the invention. FIG. 6A is a 3Ddepiction of a blunting element in accordance with an embodiment of theinvention. FIG. 6B is a longitudinal section of a blunting element in acrimped state in the lumen in accordance with an embodiment of theinvention. FIG. 6C is a longitudinal section of a blunting element inits deployed state in accordance with an embodiment of the invention.FIG. 6D is an isometric depiction of a blunting element 600 in itsdeployed state in accordance with an embodiment of the invention.

FIGS. 7A and 7B show a coiling “tip covering” blunting element inaccordance with an embodiment of the invention. FIG. 7A is alongitudinal section of a blunting element in its crimped state inaccordance with an embodiment of the invention. FIG. 7B is alongitudinal section of a blunting element in its deployed state inaccordance with an embodiment of the invention.

FIGS. 8A-8E show a “tip completing” blunting element in accordance withan embodiment of the invention. FIG. 8A is a 3D depiction of a bluntingelement in accordance with an embodiment of the invention. FIG. 8B is alongitudinal section of a blunting element in its crimped state inaccordance with an embodiment of the invention. FIG. 8C is alongitudinal section of blunting element in its deployed state inaccordance with an embodiment of the invention. FIGS. 8D and 8E are 3Ddrawings showing the same as FIGS. 8B and 8C, respectively.

FIGS. 9A-9D show an “internal sheath” blunting element in accordancewith an embodiment of the invention. FIG. 9A is a longitudinal sectionof a blunting element in its crimped state in accordance with anembodiment of the invention. FIG. 9B is a longitudinal section of ablunting element in its deployed state in accordance with an embodimentof the invention. FIGS. 9C and 9D are 3D drawings showing perspectiveviews of FIGS. 9A and 9B, respectively.

FIGS. 10A-10D show an “internal sheath” blunting element in accordancewith an embodiment of the invention. FIG. 10A is a longitudinal sectionof a blunting element in its crimped state in accordance with anembodiment of the invention. FIG. 10B is a longitudinal section ofblunting element 900 in its deployed state in accordance with anembodiment of the invention. FIG. 10C is a 3D drawing of a deployedblunting element without a needle in accordance with an embodiment ofthe invention. FIG. 10D is a 3D drawing of a deployed blunting elementwith a needle in accordance with an embodiment of the invention.

FIGS. 11A and 11B show a “sandwich sheath” blunting element inaccordance with an embodiment of the invention. FIG. 11A is alongitudinal section of a blunting element in its crimped state inaccordance with an embodiment of the invention. FIG. 11B is alongitudinal section of a blunting element in its deployed state inaccordance with an embodiment of the invention.

FIG. 12A shows a simple linear mechanical guide used for guiding thecannulation procedure in accordance with an embodiment of the invention.

FIG. 12B shows a simple rotary mechanical guide used for guiding thecannulation procedure in accordance with an embodiment of the invention.

FIGS. 13A-13D show an ultrasonic transducer used as part of acannulation device in embodiments of the invention. FIG. 13A is asimplified 3D drawing of a cannulation device having a transducer inaccordance with an embodiment of the invention. FIG. 13B shows atransducer used as part of a cannulation device in embodiments of theinvention. FIGS. 13C and 13D are simplified side views of cannulationdevices having a transducer in accordance with embodiments of theinvention.

FIG. 14 shows a cannulation device having a guidance system inaccordance with embodiments of the invention.

FIG. 15A shows a longitudinal cross section of a cannulation device inaccordance with one embodiment of the invention.

FIG. 15B shows a longitudinal cross section of a cannulation device inaccordance with one embodiment of the invention.

FIG. 16 shows a cannulation device having a robotic system in accordancewith embodiments of the invention.

FIG. 17 shows an expandable sheath in accordance with an embodiment ofthe invention.

FIG. 18 shows another expandable sheath in accordance with an embodimentof the invention.

FIG. 19 shows yet another expandable sheath in accordance with anembodiment of the invention.

FIG. 20 shows an expandable sheath in accordance with an embodiment ofthe invention.

FIG. 21A shows a 3D schematic depiction of a tube in accordance with anembodiment of the present invention.

FIG. 21B depicts a spirally folded sheath in accordance with anembodiment of the present invention.

FIGS. 22A-22D show a sheath with multiple micro-corrugations inaccordance with an embodiment of the present invention.

FIGS. 23A-23C show a sheath with larger corrugations in accordance withan embodiment of the present invention.

FIGS. 24A-24G show a sheath with a single longitudinal corrugation inaccordance with an embodiments of the present invention.

FIG. 25 shows the distal end of a cannulation device in accordance withembodiments of the invention where a catheter is placed over the needleat the distal end of the cannulation device.

FIG. 26 illustrates an example of a computer system 1600 that may beconfigured to practice an embodiment of the invention.

DETAILED DESCRIPTION

The invention relates to devices and methods for the cannulation of bodylumens, in particular blood vessels, with the goal of placingintravascular catheters such as Central Venous Catheters (CVCs),Peripherally Inserted Central Catheters (PICVs), midlines, andPeripherally Inserted Venous Catheters (PIVCs). The invention alsorelates to devices and methods for temporary vessel cannulation withoutplacing an indwelling catheter, with the goal of blood sampling,cardiovascular monitoring, or administration of drugs or fluids. Variousbody lumens and/or cavities and/or various indications for use involvingblood, cardiovascular, drugs or fluids are contemplated.

Mechanical Vessel Cannulation Device

FIG. 1A is a longitudinal cross section of the mechanical cannulationdevice 1000 of the invention, which depicts the guidewire advancementmechanism in a cocked position. FIG. 1A′ is a longitudinal cross sectionof a mechanical cannulation device in accordance with embodiments of theinvention, which depicts the guidewire advancement mechanism in adeployed position. FIG. 1B is a top view of FIG. 1A. In these figures,distal refers to the left side, and proximal refers to the right side.

More particularly, FIG. 1A is a longitudinal section of device 1000along its midline, which passes along the line marked 1 in the top viewshown in FIG. 1B. FIG. 1A shows device 1000 which may include from leftto right the following main parts: needle adapter 10, seal 16, body 20,guidewire advancement mechanism 30 a (shown in cocked position), largespring 40, and backplate 50. Each of the main parts has a central lumenand guidewire 1 may be slideably positioned within the central lumen ofall the above parts.

Device 1000 may further include membrane 60, lever 70, sear 80, cover90, cocking handle 100, and adjustment element 110. Each main part ofdevice 1000 is further described below.

Needle adapter 10 may include luer adapter 11, lumen 12, o-ring slots 13and 14, distal fluid passageway 15, and seal 16, which may optionally bean integral part of needle adapter 10. O-rings may be placed in o-ringslots 13 and 14 to prevent pressure within fluid passageways fromescaping around needle adapter 10.

Body 20 may include slider slot 21, cocking handle slot 22, handlegroove 23, insertion groove 24, opening 25, protrusion 26, proximalfluid passageway 27, membrane groove 28, and stopper 29. Distal fluidpassageway 15 and proximal fluid passageway 27 may be connected and maybe in fluid communication with lumen 12 such that when fluid enterslumen 12 at the distal end, fluid may travel to distal fluid passageway15 and to proximal fluid passageway 27.

Guidewire advancement mechanism 30 (shown as 30 a in the cocked positionin FIG. 1A and 30 b in the deployed position in FIG. 1A′) may includeslider 31, which may have slider proximal end 32 and slider distal end33, gripper 34, which may have gripper distal end 39, gripper distal end35, and gripper lumen 36, ring 37, and small spring 38. Gripper 34 maycomprise a tubular structure, longitudinally divided into two or moreparts. Gripper distal end 35 may comprise the distal ends of theselongitudinal parts, which may be made with a tendency to expandradially. Small spring (or “gripper spring”) 38 may typically be acompression spring having a force of 1-2 N at its free state. In anembodiment, the gripper spring 38 may include a free length ofapproximately 20 mm, a solid length of 9.5 mm, 8 active coils out of 20total, 0.45 mm diameter ss 312 wire, and a coil outer diameter of ˜4.5mm. Ring 37 may be slideably disposed within slider 31, and over gripper34, such that when positioned over gripper distal end 35, it may preventradial expansion of gripper distal end 35, thus decreasing the diameterof gripper lumen 36 (marked 36 a), and gripping wire 1. Conversely, whenring 37 is pushed proximally relative to slider 31, distal end 35 ofgripper 34 may radially expand, enlarging the diameter of gripper lumen36 (marked 36 b), and releasing guidewire 1.

As shown in FIG. 1A, when in its cocked (proximal) position, guidewireadvancement mechanism 30 a may comprise compressed gripper lumen 36 a,gripping guidewire 1 so that it can be advanced by the device 1000. Moreparticularly, in the cocked position, with a guidewire loaded withingripper lumen 36 a, ring 37 may be pushed by small spring 38 a towarddistal end 35 a of gripper 34 such that 37 protrudes distally beyondslider distal end 33, and compresses the longitudinal part whichincludes gripper end 35 a.

Large spring 40 is positioned between guidewire advancement mechanism 30and backplate 50, such that in the cocked position large spring 40 a iscompressed and exerts forward pushing force on guidewire advancementmechanism 30 relative to backplate 50. In the deployed position, largespring 40 exerts a smaller force on guidewire advancement mechanism 30b, but such a force that is sufficient to compress small spring 38 b andcause release of guidewire 1 from gripper 34. Large spring (or “sliderspring”) 40 may be a compression spring having a force of ˜10 N at itssolid length and ˜3 N at the deployed state, which may typically be at alength of ˜78 mm. Typical specifications may further include a freelength of approximately 98 mm, a solid length of ˜33 mm, 34 activecoils, 0.8 mm diameter ss 312 wire, and a coil outer diameter of ˜9.7mm.

Backplate 50 has a through hole 51 for passage of guidewire 1.

Membrane 60 may be a thin membrane having an oblong fold which fits intomembrane groove 28 of body 20. Membrane 60 may be held in place by frame65 which presses membrane 60 onto body 20. Proximal fluid passageway 27may be in direct contact with membrane 60 such that when fluid entersproximal fluid passage way, membrane 60 may sense the change ofpressure. Membrane 60 may be a diaphragm.

Lever 70 is an elongate member with a lever hinge 71 running throughprotrusion 26 of body 20, a lever tooth 72, and a lever base 73. Leverbase 73 fits inside membrane frame 65, and sits flat on membrane 60while deflated. If pressurized fluid enters between membrane 60 and body20 via fluid passageways 15 and 27, membrane 60 can inflate and rise,and lever 70 can rotate around lever hinge 71, such that lever tooth 72moves upwards. The exact angle of the contact surface of lever tooth 72with sear 80, relative to the line perpendicular to the long axis ofslot 21, can be very important. This angle, combined with otherparameters which include the position of hinge 71, position of uppersear tooth 83, position of lever tooth 72, govern the size and directionof a moment which tends to turn lever arm 70 around hinge 71. To keepthis moment at a clockwise direction, the resultant reaction force ofsear 80 through lever 70 may be directed above hinge 71. The distancebetween the vector of this force and the hinge multiplied by the vectorsize, is the rotating moment. The desirable rotating moment is governedby the location of the membrane relative to hinge 71, the size ofmembrane 60, and the desired triggering fluid pressure. Adjustmentmechanism 110 also effects, and preferably adjusts, the desired rotatingmoment. In some embodiments, the resultant rotating moment from the searreaction on lever tooth 72 can be between 1250 and 7500 gf-mm (gramforce millimeter).

Sear 80 has a hinge 81 running through body 20, and around which it canrotate. Sear 80 also has lower sear tooth 82, upper sear tooth 83, andsear hole 84. Sear 80 is positioned inside opening 25 of body 20, suchthat lower sear tooth 82 protrudes into slot 21 when sear is upright asin FIG. 1A, and no part of sear 80 protrudes into slot 21 when it issufficiently rotated to either side (approximately 30-90 degrees).

A spiral spring (not shown) may be placed with its coils around searhinge 81, one leg in sear hole 84, and the other leg in a hole in body20, such that sear 80 can be slightly rotated around sear hinge 81, buttends to flexibly return to the same angle relative to body 20. Thisallows moving guidewire advancement mechanism 30 along slot 21 from thedeployed (distal) position to the cocked (proximal) position withoutsear 80 obstructing its passage.

Cover 90 can be a thin walled shell covering the upper part of device1000, including lever 70, membrane 60, sear 80, and adjustment mechanism110. Cover 90 may prevent a user from inadvertently touching thesensitive parts of device 1000 and interfering with device operation. Itmay also provide convenient grips for holding the device. Cover 90 mayoptionally include cover slot 91. A safety latch (not shown) in the formof a rigid, semi-rigid, or flexible thin rod may be placed through coverslot 91, to press lever 70 clockwise, and enable cocking of device 1000as explained below.

Cocking handle 100 may comprise plate 101, handle 102, and hook 103.Plate 101 may fit into handle groove 23, but may be slightly wider thancocking handle slot 22, and therefore needs to be inserted into handlegroove 23 via insertion groove 24. Cocking handle 100 may be placed withhook 103 distal to guidewire advancement mechanism 30, so that whencocking handle 100 may be moved proximally, hook 103 may pull guidewireadvancement mechanism 30 proximally.

Optional adjustment element 110 may include knob 111, casing 112, cap113, and knob spring 114. Knob 111 and knob spring 114 may enclosewithin casing 112 and cap 113, such that knob 111 may push upwards byknob spring 114. Casing 112 may have an external thread with body 20,and an internal thread with cap 113. Adjustment element 110 may beplaced in an opening in body 20 such that knob 111 may apply upwardsforce on lever 70, reducing the force required for release of guidewireadvancement mechanism 30, thereby reducing the blood pressure thresholdat which device 1000 may deploy. The force applied by adjustmentmechanism 110 may be adjusted by changing knob spring 114, by screwingcap 113 tighter or weaker, or by screwing casing 112 upward or downwardrelative to body 20.

Adjustment element 110 may have an end force of 50-300 grams, preferably100-200 grams, and a travel of 1-5 mm, preferably 2-4 mm.

Access to adjustment element 110 may be from either the bottom part ofdevice 1000, for example by inserting a screwdriver through slot 22 andturning cap 113, or by removing cover 90, and rotating casing 112, whichmay be accessed from either side of lever 70. These actions may beperformed as part of the precalibration process described below.

A needle (not shown) may be coupled to the luer adapter 11 of needleadapter 10 at the distal end of device 1000. The needle may be fluidlycoupled to the distal fluid passageway 15 and/or may include a lumen forpassing guidewire 1 and fluid. Device 1000 may also be adapted toreceive bodily fluid through the needle into the anterior lumen.

An internal or external sheath (not shown) or other blunting elementsmay also be coupled to the needle. Sheaths and blunting elements arefurther discussed below.

FIG. 1A′ shows device 1000 in its deployed state. More particularly FIG.1A′ is a longitudinal section of device 1000 along its midline, whichpasses along the line marked 1 in the top view shown in FIG. 1B. Shownin FIG. 1A′ are the same elements shown in FIG. 1A with the followingdifferences: advancement mechanism 30 is shown in its distal, deployedstate, 30 b, and large spring 40 is shown in its deployed state, 40 b.

At the moment of deployment, membrane 60 may extend upwards and pushlever base 73 and lever 70 upwards, so that lever tooth 72 may movebeyond the edge of sear tooth 83, and allow sear 80 to rotate clockwise,allowing advancement mechanism 30 to be pushed distally by large spring40 and advance guidewire 1. The extent to which lever 70 may moveupwards during deployment is marked by dashed line DL, and the extent towhich sear 80 may rotate is marked by dashed line DS.

As shown in FIG. 1A′, when guidewire advancement mechanism 30 b is inits deployed (distal) position, large spring 40 b may push ring 37against stopper 29 of body 20, so that ring 37 may be pressed intoslider 31, and distal end 35 b of gripper 34 may protrude distallybeyond ring 37, such that its longitudinal parts may expand radially andenlarge the diameter of gripper lumen 36 a, thus releasing guidewire 1to slide undisturbed within gripper lumen 36 b.

Moving now to FIG. 1B, which is a top view of device 1000 with cover 90removed, the following parts are seen, from left to right: guidewire 1,luer adapter 11, body 20, protrusion 26, lever 70, membrane 60, membraneframe 65, lever base 73, adjustment mechanism 110, optional fluid port,opening 25, ring 37, sear 80, slider 31, and backplate 50. Fluid port120 may be a port in fluid communication with the area between membrane60 and body 20, and which may consist of a unidirectional valve, and mayinclude a luer connector or any other connector. This port may be usedto fill fluid in the fluid passageways, either immediately prior to use,or as part of device assembly and preparation during manufacturing.Also, this port may be useful for cleaning the device after use.

In operation, device 1000 may be precalibrated, it may be cocked beforeuse, and then used to access a blood vessel.

FIG. 1C is a top view of an embodiment of membrane 60 of device 1000.More particularly, FIG. 1C shows membrane 60, which may be substantiallyoblong, although it may have other, preferably elongate shapes, such aselliptical. Such shapes are compatible with the general elongatestructure of device 1000. Membrane 60 may typically comprise oblong foldOF, which may be designed to fit within membrane groove 28 of body 20.Membrane 60 may typically extend around oblong fold OF, to enable it totightly and sealably be attached to body 20 by frame 65, preventingleakage around its edges. Typically, membrane 60 may further comprisemultiple holes H which may allow tightening frame 65 to body 20, usingscrews, pins, pegs, or other components as known in the art.Longitudinal midline LM and cross-section midline CM are further show inFIG. 1C.

FIG. 1D is a longitudinal section view of membrane 60 of device 1000.More particularly, FIG. 1D is a longitudinal section along line LM shownin FIG. 1C. Oblong fold OF is shown, defining an effective membranelength L.

FIG. 1E is a longitudinal section view of membrane 60 of device 1000.More particularly, FIG. 1E is a cross section along line CM shown inFIG. 1C. Oblong fold OF is shown, defining an effective membrane widthW.

Membrane 60 may typically be made of a thin layer of elastic materialsuch as silicone, polyurethane, latex, etc. Membrane 60 may typicallyhave a durometer of 5 to 30 shore A, preferably 10 to 20 shore A. Thethickness of membrane 60 may typically range between 0.05 mm and 0.5 mm,preferably 0.2 to 0.4 mm.

Effective membrane length L and effective membrane width W define theeffective membrane surface area, which define the force it may applyover lever base 73. Oblong fold OF of membrane 60 may allow membrane 60to rise without being elastically stretched. This may be beneficial asit may reduce the pressure required for triggering the trigger mechanismof device 1000. If membrane 60 did not have OF, pressure would initiallyneed to work against the elasticity of membrane 60, stretch it, and onlythen would it act upon lever base 73.

Precalibration

The needle and guidewire to be used with device 1000 are assembled onthe device. A needle is placed with its hub over luer adapter 11, andguidewire 1 is loaded through lumen 12, guidewire advancement mechanism30, and hole 51, and the device is in a cocked position. Increasingfluid pressures may be intermittently applied to device 1000 through theneedle, and the pressure at which deployment occurs instantaneously isnoted as the threshold pressure. Adjustment mechanism 110 may beadjusted as described above to increase or decrease the thresholdpressure.

Cocking Action

During cocking action, a safety latch as described above may preferablybe placed in cover slot 91 to hold lever 70 in the proper position.Guidewire 1 may be loaded through a needle (not shown), lumen 12,guidewire advancement mechanism 30, and hole 51, and may be positionedsuch that its distal tip protrudes approximately 2-5 cm distal to thedistal tip of the needle. Cocking handle 100 may be moved proximally bythe user, such as by placing a user's thumb in front of handle 102 andpulling it proximally to a marking on body 20, or all the way untillarge spring 40 may become completely compressed. At that point,guidewire advancement mechanism 30 a may be proximal to sear 80, andcocking handle 100 may be returned forward to its distal location. Oneor more additional spring may be added to perform this return movementby releasing the handle. As guidewire advancement mechanism 30 is pusheddistally by large spring 40, slider distal end 33 may engage lower seartooth 82, and may attempt to rotate sear 80 clockwise. Since a safetylatch may be placed inside cover slot 91, lever 70 may be held in aposition such that lever tooth 72 engages with upper sear tooth 83.Thus, guidewire advancement mechanism 30 may remain in its cockedposition, and device 1000 may become ready for use. The safety latch maythen be removed from the cover slot 91.

Vascular Access

An over the needle sheath in accordance with the present invention mayoptionally be placed over the needle of device 1000, preferably prior tococking the device.

The target vessel and puncture area may be chosen, optionally usingimaging, and the skin may be prepped as customary. The safety latch maybe removed prior to skin puncture.

The user may then puncture the skin and attempt to puncture the targetvessel. Once a vessel with intravascular pressure above a precalibratedthreshold pressure is punctured, pressure may be transmitted to membrane60 which may rise and push lever 70 upward away from the advancementmechanism and automatically triggering release of guidewire advancementmechanism 30 by allowing sear 80 to rotate sufficiently clockwise, thusadvancing guidewire 1 into the vessel, and preventing the needle fromexiting through the back side of the vessel. The user can then furtheradvance guidewire 1 into the vessel, slide the over the needle sheathinto the vessel, and remove device 1000 and guidewire. As furtherprovide below, the needle sheath may be an external sheath over theneedle or an internal sheath within the needle. In some embodiments, theneedle sheath may be an expandable sheath to aid the placement ofcentral catheter.

Additional features of the current invention are described below.

Fluid Passageways

For optimal function of device 1000, fluid passageways 15 and 27 shouldbe as short and straight as possible, without bends, and with a diameterthat is small enough to keep total volume small, but large enough so asnot to increase resistance to fluid pressure transmission. For example,in some embodiments, the fluid passageways 15 and 27 may have a capacityfor 5 cubic millimeters to 25 cubic millimeters total fluid, or from 5to 20 cubic millimeters, or from 5-10 cubic millimeters. In someembodiments, the fluid passageways diameter may be 0.5 mm-2.5 mm,preferably 0.75 mm-2 mm, and their length may be less than 4 cm,preferably less than 2.0 cm. Prefilling the fluid passageway with abiological acceptable fluid, such as saline, may further improvefunction of the device.

Trigger Mechanism

The trigger mechanism includes lever 70 and sear 80. In order to keepresponse times low, these parts should have low inertia. Additionally,in order to achieve high accuracy, parts should be rigid and have lowfriction, and be built to tight tolerances. Possible materials for theseparts may include, among others, aluminum, stainless steel, titanium,and PEEK. Polishing of the contact areas between lever 70 and sear 80may further decrease friction and reduce triggering force and pressurethreshold.

Adjustment Mechanism

The adjustment mechanism adds a rotating moment to the lever, changingthe moment balance in such a way that either reduces or increases therequired force from the membrane to trip the trigger mechanism.

The adjustment mechanism may include adjustment element 110 and be usedas described above in the pre-calibration section. The adjustmentmechanism may alternatively comprise other elements that may applyforces to the lever or sear from other directions, for example fromcover 90 downwards. Regardless of the exact mechanism of adjustmentmechanism, it may comprise a scale, which may allow recording ofadjustments and comparison between devices.

In some embodiments, adjustments of the adjustment mechanism may beperformed during manufacturing. Preferably, tolerances of the system aresuch that once a specific model of device is manufactured andprecalibrated, all similar devices may be adjusted to the same settings,and will all function similarly. Alternatively, each device may beprecalibrated individually during manufacturing.

Advancement Mechanism

Advancement mechanism 30 described above, may allow for guidewire 1 tobe gripped by gripper 34 at all times, until the end of the deploymentstroke. Once fully deployed, the guidewire may be released and can bemoved freely by the user. The advantage of such an advancement mechanismis that advancement of the wire is controlled, i.e., it is known thatthe wire may advance at least the distance of the stroke of theadvancement mechanism, 2-10 cm, preferably 3-6 cm. In addition, at theend of motion, the guidewire may be moved without friction with thedevice, so the user can both assess that it is within a vessel, anddecide to insert it further or pull it back if required.

Conversely, other advancement mechanisms described in the art mayrelease the guidewire at an earlier point during advancement, which maydecrease control over the insertion distance.

Noise/Recoil Dampening

In an embodiment, at least the distal end of ring 37 is made of, or iscovered by, a soft material such as silicone. This may dampen the impactthat may occur between ring 37 and stopper 29 of body 20 when device1000 deploys and guidewire advancement mechanism 30 moves to its distalposition (30 b). In another embodiment, such soft material may bepositioned on stopper 29, instead of, or in addition to, over ring 37.Such impact absorbing elements may optionally further have a shapeimproving their impact absorbing properties such as a c-shaped crosssection or accordion-like longitudinal section.

Alternatively or additionally, the impact-absorbing element may be madeof an aerated material such as sponge, and may have an elongate shape,for example a cylindrical shape.

In yet another embodiment, the impact absorbing element and seal 16 maybe connected to each other or made as one part.

Lowering the mass of guidewire advancement mechanism 30 is an additionalmeasure for decreasing recoil and noise during deployment.

Cocking Mechanism

The above described cocking mechanism has the advantage of simplicity inboth mechanism and in the cocking action performed by the user. Inaddition, no parts that move during deployment are exposed, so that theuser may not inadvertently interfere with movement of the advancementmechanism.

Preferred components for this mechanism include sear 80 (protruding intoslot 21 only in the cocked position), its springy recoil to an anglewhere sear tooth 82 protrudes into the slot 21, preferably ˜45 degreesin the direction from distal superior to proximal inferior (the anglebetween sear teeth longitudinal axis to slot 21 longitudinal axis),downward (clockwise) force over lever 70 (in some embodiments exerted bythe above described safety latch, but can be exerted by different safetylatches), and the cocking handle.

More particularly, a spiral spring for ensuring the sear tooth anglethat was described above, having coils around sear hinge 81, one leg insear hole 84, and the other leg in a hole in body 20, such that sear 80can be slightly rotated around sear hinge 81, but tends to flexiblyreturn to the same angle relative to body 20. This spiral spring maytypically be a torsion spring with two legs, having a torque force of˜4.2 Nmm at its free state. Typical specifications may further include2.5 coils, 0.4 mm diameter ss 312 wire, and a coil outer diameter of˜5.4 mm.

Cover

Described above, cover 90 can be made of various materials such as ABS,polycarbonate, other plastics, stainless steel, aluminum, or othermetals, or any other appropriate material, or combination of these.Beneficially, it may be transparent to allow viewing of mechanismmovement. It may be connected to body 20 using glue, screws, a snapdesign or combination thereof.

The current design incorporates a safety latch or inserted pin into thecover 90 in cover slot 91. Said safety latch preventing inadvertentactuation of the trigger mechanism.

Disposable/Reusable

In many situations, it may be beneficial that the parts of the device incontact with the patient's blood are disposable, while those not incontact with blood remain reusable.

Four preferred embodiments of a mechanical vessel cannulation deviceconsisting of a combination of reusable and disposable parts are shownin FIGS. 2A-2D.

FIG. 2A is a longitudinal cross section of device 1000 wherein lever 70,sear 80, and adjustment mechanism 110 are reusable, and all other maincomponents are disposable. Line A is a possible separation line dividingdevice 1000 into a reusable section (above line A), and a disposablesection (below line A). The two parts may be slideably positioned overeach other, and locked together using a latch, a snap element, or othermeans as known in the art. In this embodiment, lever 70 and sear 80 thatrequire high precision may be manufactured using expensive materials andprocesses. However, large spring 40 and advancement mechanism 30 arestill disposable, which adds to the disposable cost.

FIG. 2B is a longitudinal cross section of device 1000 wherein lever 70,sear 80, adjustment mechanism 110, large spring 40, advancementmechanism 30, and body 20 are reusable, and all other main componentsare disposable. Line B is a possible separation line dividing device1000 into a reusable section (to the right of line B), and a disposablesection (to the left of line B). In this embodiment, a guidewire is notused; instead, an external sheath may be used to blunt the needle. Itmay be pushed forward by push element 200, which is part of thedisposable section, and may be advanced by advancement mechanism 30. Inthis embodiment a valve is not required as no element is pushed throughthe needle.

FIG. 2C is a longitudinal cross section of device 1000 wherein lever 70,sear 80, adjustment mechanism 110, large spring 40, slider 31, and body20 are reusable, and all other main components are disposable. Part Cincludes membrane 60, membrane frame 65, and that part of body 20supporting membrane 60 and including proximal fluid passageways 27. PartC may be slid in from the side and locked to body 20. Part D comprisesneedle adapter 10, seal 16, and stopper 29. Parts of advancementmechanism 30, including ring 37, gripper 34, and small spring 38,together with guidewire 1 and part D are plugged into device 1000 fromits front (distal) side. A nylon sheath 201 connects stopper 29 withring 37, and another nylon sheath 202 covers guidewire 1 from theproximal end of gripper 34 to the proximal end of guidewire 1, to keepguidewire 1 sterile at all times. In this embodiment, opening 51 ofbackplate 50 is made larger to accommodate passage of sheath 202 andguidewire 1. In case slider 31 is made disposable such that alladvancement mechanism 30 is disposable, hook 103 of cocking handle 100is able to fold to one side, enabling insertion of advancement mechanism30, and still enabling pulling it back for cocking device 1000.

FIG. 2D is a longitudinal cross section of device 1000 wherein lever 70,sear 80, adjustment mechanism 110, large spring 40, slider 31, and body20 are reusable, and all other main components are disposable. Thisembodiment has two separate slots for advancement. Slot 21, whereinslides slider 31 pushed by large spring 40, and a separate slot 210,wherein slides gripper 34, pushed by arm 211 extending from slider 31.An embodiment of a device 1000 comprising disposable and reusablecomponents as described in FIG. 2D, is shown in FIG. 2Di.

More particularly, FIG. 2Di is a perspective view of cannulation device1000 having a disposable component E comprising membrane 60, membraneframe 65, and that part of body 20 supporting membrane 60, proximalfluid passageways 27, needle adapter 10, seal 16, and stopper 29. Needle2 is seen connected to luer adapter 11 and extending distally from it.Guidewire 1 is seen protruding proximally from gripper 34, and coveredby sterile cover 202. A socket 220 is located in the front of body 220.Whereas in other embodiments socket 220 may comprise a thread enablingconnection of needle adapter 10 to body 20 using a screw, in someembodiments such as the one in FIG. 2Di, a spring loaded pin 221 in thedisposable part E may be used to temporarily connect part E to body 20.Alternatively other easily removable connecting means as known in theart may be used such as various forms of buttons and fasteners.

Part E includes membrane 60, membrane frame 65, and that part of body 20supporting membrane 60, proximal fluid passageways 27, needle adapter10, seal 16, and stopper 29. Parts of advancement mechanism 30,including ring 37, gripper 34, and small spring 38, together withguidewire 1 and part E are plugged into device 1000 from its front(distal) end. Nylon sheath 202 covers guidewire 1 from the proximal endof gripper 34 to the proximal end of guidewire 1, to keep guidewire 1sterile at all times. In use, part E complete with the needle andguidewire is plugged into device 1000 from its front end as shown by thearrow in FIG. 2Di, such that guidewire 1 covered by sterile cover 202protrudes out of hole 51 at the back end of the device.

A similar combination of disposable and reusable parts may be used forsome electronic variations of the device 1000 which are described below.

By separating slider 31 from gripper 34 such that large spring 40 is notcoaxial with the needle and guidewire 1, it is possible to make almostall of the advancement mechanism including large spring 40 reusable,thus lowering the cost of the disposable parts, while keeping theblunting element (in this case a guidewire, but possibly a differentintravascular element) sterile.

In FIG. 2D slot 21 is depicted above slot 210, but these can be one nextto the other or in any other configuration.

A cocking handle is not shown in FIG. 2D, but it can be placed forexample on the side of slot 21.

Aft Hinge Design

In another embodiment shown in FIGS. 2E and 2F, the direction of thelever is reversed, so that the membrane force has a significantlygreater torque than does the friction force between the lever and searteeth, leading to a more predictable activation pattern.

More particularly, FIG. 2E is a longitudinal cross section of device1000′, which is identical in most details to device 1000 as shown inFIG. 1A, with the following differences: lever 70′ has hinge 71′ whichruns through protrusion 26′, located at the rear (proximal) part ofdevice 1000′, so that lever tooth 72′ is between hinge 71′ and leverbase 73.

FIG. 2F is a top view of device 1000′, showing the same elements.

In this embodiment, the force exerted by membrane 60 on lever base 73has a longer arm from hinge 71′ than does the friction force betweenlever tooth 72′ and sear tooth 83, whereas in the embodiment shown inFIG. 1, the situation is the opposite. Therefore, in the currentembodiment, the moment of force created by membrane 60 for lifting lever70′ is much larger than that of the opposing friction forces at levertooth 72′. In other words, in this embodiment the membrane 60 is givenan advantage over friction forces.

In this embodiment, changes in friction force between the lever and searteeth have a minor effect on the force required for release of thetrigger mechanism, and consequently on threshold pressure. Such changesin friction force may occur often due to various reasons such asvariations in ambient temperature or humidity, in material properties,or in the forces applied by spring 40 and the spiral spring on sear 80.Thus, the current embodiment provides means for increasing the accuracyof deployment threshold.

This embodiment differs from previous embodiments in that because thehinge 71′ is located further away from membrane 60 than hinge 71, evenif the distance to which lever tooth 72′ must move to activate thetrigger mechanism is the same as lever tooth 72′ in device 1000, thevolume of fluid that must enter membrane 60 in order to produce thismovement could be slightly larger, and might cause a different triggerresponse time.

The design can be modified by shortening the length of overlap betweenlever tooth 72′ and sear tooth 83. This would decrease the requireddistance of movement and consequently the volume of fluid that mustenter the membrane.

In an embodiment, the distance between the center of membrane 60 (orlever base 73) to hinge 71′ is approximately double the distance betweenlever tooth 72′ to hinge 71′. The ratio between these distances may be1.2 to 4, preferably 1.5 to 3.

Electronic Vessel Cannulation Device

In another embodiment of the present invention, a vessel cannulationdevice utilizing electronic sensing and triggering is provided.

FIG. 3A is a schematic longitudinal section of electronic vesselcannulation device 2000 that can include or be utilized in conjunctionwith a processor, such as a computer. The structure of this device isgenerally similar to the mechanical device described above. Body 320contains large spring 340, which pushes advancement mechanism 330distally to advance guidewire 1, passing through valve 316 and needle.Fluid passageway 315 may lead from the lumen of the needle adapter to anelectronic sensor 400, which may be a pressure sensor. The sensor maytransmit its output to a CPU 410 which controls solenoid 420 (or othertype of actuator), which is operably connected to trigger mechanism 430.

FIG. 3B is a schematic longitudinal section of an exemplary triggermechanism 430 of device 2000. Slider 331 is seen within slot 321.Solenoid 420 is located outside the slot, and is connected such that itcan pull lever 483 which may move levers 482, 481, and sear 480. Sear480 has a tooth protruding into slot 321, which may engage with slider331 in its cocked position, preventing its forward movement. Sear 480and the levers are structured such that all the force of large spring340 may transfer to the hinge of lever 481 without any torque around it,and therefore very little force is required to be exerted by solenoid420 to release this trigger.

When device 2000 is used to puncture a vessel, sensor 400 may measurepressure or any other physiological parameter of blood or other fluid orgas at the needle tip or entering the needle. CPU 410 may be configuredto execute computer-readable instructions to cause the device to analyzedata sent by sensor 400. As further detailed below, device 2000 may beconfigured to be pre-set to identify parameters unique to arteries,veins, or other body cavities or organs, for example a specific pressurethreshold or range. If predetermined criteria are met, CPU 410, whenexecuted, may be configured to activate solenoid 420, which pulls lever483, which eventually leads to clockwise rotation of sear 480, andrelease of slider 331, with advancement of advancement mechanism 330 andguidewire 1 or other blunting element.

In another embodiment shown in FIG. 4, the same trigger mechanismdescribed above for the mechanical cannulation device may be used, whilesensing and activation of the trigger mechanism are electronic.

FIG. 4 is a longitudinal section of device 2000 similar in structure tothe one shown in FIG. 1A. In some embodiments, membrane 60 and frame 65may be replaced with sensor 400, which is connected to proximal fluidpassageways 315. Sensor 400 may also be connected to CPU 410, which mayalso be connected to solenoid 420.

In the current embodiment, solenoid 420 is connected to a rod 500 with awedge shaped tip, which is positioned at the meeting point of sear 380and lever 370.

In operation, when fluid enters fluid passageways 315, CPU 410 activatessolenoid 420, and rod 500 is pushed distally (i.e. left in this figure),and disengages lever 370 from sear 380, causing sear 380 to turnclockwise and releases advancement mechanism 330.

Electronic Advancement Mechanisms

In the above embodiments, advancement of the blunting element may bedone mechanically. However, in some embodiments this may be achieved byelectronic means. For example, a linear motor, large solenoid, or anyother electronically activated device capable of linear motion could beused to advance advancement mechanism 330. Alternatively, rotary motorscould roll the wire or advancement mechanism forward.

Sensor

Sensors used in the embodiments of the invention may be pressuresensors, temperature sensors, conductivity sensors, flow sensors,ultrasound sensors, pH sensors, optical sensors, or any other sensors asknown in the art.

In some embodiments, at least a pressure sensor may be used. Samplingrate and communication speed between the sensor and CPU are of utmostimportance, as a low sampling rate, or delayed communications might leadto delayed device responses, which could cause deployment outside of thevessel or other malfunctions.

As the relevant time scale of pressure changes in this application areseveral milliseconds, a sampling rate of 10 KSPS (Kilo samples persecond) may be sufficient for most embodiments described herein, whilefor embodiments requiring more advanced signal analysis, a highersampling rate is preferred.

The delay between the time of sampling to receipt of data by the CPUshould be kept to a minimum, as response time to the pressure changeshould be short to avoid deployment outside of the vessel or othermalfunctions.

A differential pressure sensor is preferred, as only the relativepressure between the internal pressure of the vessel and the ambientpressure is relevant to the measurement. A+/−400 mbar (300 mmHG)differential pressure measurement is sufficient, as the pressure insidethe vessel will always be within this range.

A suitable sensor for this application may for example be the HoneywellAmplified Basic Pressure sensor #X210907, with a differentialpressure+/−400 mbar (300 mmHG) and 0.42 ms response time.

The sensor may be located as close to the target tissue as possible,that is, at the needle tip if possible, at the needle hub, or on thedevice as close as possible to the needle hub. Placing the sensor on thedevice has the advantage of using standard needles, thus reducingdisposable costs.

In some embodiments, a combination of several sensors may be used. Thismay enable using a combination of physiological parameters at the needletip to more accurately identify a specific body cavity, and initiateaction.

Flow Chart

FIG. 5A is a flow chart of a process which may be implemented by thedevice of embodiments of the invention.

Step 3000:

The process may begin with calibration of the sensor to ambient pressureand temperature, which is performed prior to skin puncture. This is notalways necessary, and depends on the specifications of the sensor used.

Step 3001:

The user may then optionally select whether the target vessel is anartery or a vein. This can be performed by any input device for exampleusing a simple button on the device, or any input device describedbelow. Optionally, the device has a user interface allowing choice ofthe target vessel type, and optionally input of additional informationsuch as patient personal or clinical data. Alternatively, in someembodiments each device is either arterial or venous, i.e. it is presetto suit a specific vessel type.

Steps 3002 and 3003:

Selection of the vessel type defines parameters analyzed by the device.These may include a pressure range, for which a Lower Threshold (LTH),and an Upper Threshold (UTH) are defined. Additional parameters may forexample include a Range of Pressure Change Rate (RPCR).

Settings for an artery may be:

LTH 20 mmHg

UTH 300 mmHg

RPCR+/−400 mmHg/sec

Window 0.01 sec

Settings for a vein may be:

LTH 5 mmHg

UTH 20 mmHg

RPCR+/−100 mmHg/sec

Window 0.16 sec

These ranges are given as an example mainly used in trauma scenarios,and may be defined differently. Ranges may also be defined according tothe patient's clinical condition. For example, in a patient with rightheart failure, the range of central venous pressures may be higher andoverlap with arterial pressures. In such a case the range for a venouscannulation may for example be 5-40 mmHg, and additional measures suchas rate of pressure change and possibly other physiological parametersmay need to be taken into account.

Optionally a user will input the patient's characteristics includingage, gender, habitus, clinical situation, and possibly the purpose ofintervention, and the device may suggest an appropriate pressure range,or may choose the pressure range automatically.

Step 3004:

The CPU may be configured to process a received pressure measurementfrom the sensor, an average of measurements, or several measurements andin some embodiments may perform a running average, or other calculationto remove noise from the data. The CPU may be configured to compare thecurrent pressure value to the predefined range. If not within thatrange, the CPU may be configured to repeat this step 3004 until a vesselwith this pressure range is penetrated, which allows moving to the nextstep.

Step 3005:

A timer, such as a clock, may be used to start measuring time frompenetration of the vessel. This time measurement may serve as a timewindow during which the solenoid is not activated, and measurementscontinue, in order to confirm that the right type of vessel waspenetrated. This is mainly because when an artery is punctured, pressurein the sensor transitions between ambient to the arterial pressure,passing through the venous pressure range.

For example, if a pressure reading of 8 mmHg was received, this may befrom a vein, but could also just be a transitional pressure while thesensor goes from ˜0 mmHg to say ˜100 mmHg. If an artery was penetrated,sensor pressure may equilibrate with the arterial pressure very soon, sothat if pressure remains in the venous range after the time window hasended, this serves as an indication that a vein was punctured.

In some embodiments, ranges for the time window for a vein may be0.05-0.3 seconds, preferably 0.08-0.2 seconds. In some embodiments,ranges for the time window for an artery may be shorter, e.g., 0-0.2seconds, 0-0.1 seconds, or 0-0.05 seconds.

Step 3006:

The CPU may be configured to inquire the same question as in step 3004.If the pressure value is outside the range, this means the needle hasexited the vessel, and the process may return to step 3004.

If the pressure value is within the range, this means the needle isprobably still in the vessel, and the process may continue to step 3007.

Step 3007:

The CPU may be configured to analyze the pressure change rate betweensuccessive measurements and/or over a certain time period.

The range of pressure change rate mentioned in step 3002 for a vein(+/−100 mmHg) may vary with system design, and may be between +/−50mmHg/sec to +/−150 mmHg/sec, preferably between +/−80 mmHg/sec to +/−120mmHg/sec.

The range of pressure change rate mentioned in step 3002 for an artery(+/−400 mmHg) may vary with system design, and may be between +/−350mmHg/sec to +/−450 mmHg/sec, preferably between +/−380 mmHg/sec to+/−420 mmHg/sec.

These ranges may also vary with clinical condition, and may optionallybe calibrated according to pulse rate, arterial pressure, patientcharacteristics, and clinical status.

If the current pressure change rate is outside the predefined range,this probably means that despite the current pressure reading beingwithin the predefined pressure range, the needle has either exited thevessel, or entered the wrong vessel type (artery instead of vein) andthe process may return to step 3004.

If the current pressure change rate is within the predefined range, thismeans the needle is probably still in the vessel, and the process maycontinue to step 3008.

Step 3008:

Optionally, the CPU may configure to compare various additionalphysiologic parameter values, measured by sensors as previouslymentioned, to predefined ranges. If these parameters are found to beoutside the predefined ranges (in some embodiments, these would becompatible with intravascular conditions), the process may return tostep 3004. If within range, the process may continue to step 3009.

This step may optionally consist of multiple such stages, using multipleinputs, for example verifying intravascular conditions by measuringimpedance, pH, temperature, reflectance, and any other parameterenabling distinguishing between blood and extravascular tissues, oridentifying any other target tissue or fluid.

In some embodiments only if all parameters are within predeterminedranges, will the process continue to step 3009. Alternatively in otherembodiments, each parameter may receive a “grade” (e.g. 10 for withinrange, and decreasing as distance from range increases), and an averageor other function of these grades serves as the basis for the process'sdecision making. In yet other embodiments, each parameter may be furtherassigned a weight according to its accuracy, signal to noise ratio, orimportance, and a weighted average may be calculated.

Such use of multiple physiologic parameters, or multiple inputs, forverifying correct vessel penetration, may increase sensitivity andspecificity of the device.

Step 3009:

The CPU may be configured to check whether the time window has expired.If it has, this means that all measured parameters remained within theirpredefined ranges for a sufficient period of time, which in very highlikelihood means that the needle has penetrated, and is still in thelumen of the correct type of vessel.

If the time window has not yet expired, the process may return to step3006, and may continue monitoring the parameters as described above.

If the time window has expired, or in other words if the time fallsoutside a predetermined time window, the process may continue to step3010 to activate the solenoid.

In some embodiments, the pressure versus time graph curve contour may beanalyzed to determine whether a needle is in the correct cavity.Parameters of the pressure curve that may be analyzed, may include forexample the complete shape of the pressure-time graph, degree and rateof pressure change since assumed penetration into the vessel, thepressure change gradient, area under the pressure curve, etc.

In some embodiments, the pressure curve may be monitored for a veryshort period and it can be predicted how the curve should look beforeand after the monitoring period. Further, the shape of the measuredpressure curve can be compared to the predicted shape, thus identifyingpressure changes that are a result of entering/exiting a vessel, and notnatural pressure changes within the vessel.

In some embodiments, simultaneous ECG monitoring, which may be performedthrough the needle, or through external electrodes, is correlated withthe pressure curve, to identify “real” pressure changes within a vesselvs those resulting from entering/exiting a vessel.

In an embodiment, a bank of measurements may be used from past patients,to compare with the measured pressure curve.

In an embodiment, rapid measurements at the very start of an initialpressure rise may be used, to extrapolate whether the final pressurewould reach a venous or an arterial level. Because this is doneextremely rapidly, preferably within less than 50 milliseconds, theassumption is that in this case the needle would not have time to exitthe vessel before the solenoid is activated and the blunting device isdeployed.

In an embodiment, all or any combination of the above methods may beused, or shifts between them according to various stages of theprocedure.

FIG. 5B is a graph produced using a prototype device similar instructure to the one described in FIG. 4, and the process similar tothat described in FIG. 5A. Pressure measurements from the device'ssensor were constantly recorded on a laptop computer. In the graph,pressure (Y axis, mmHg) is plotted against time (X axis, seconds), fromright to left. LTH and UTH are plotted as straight lines, and solenoidactivity is plotted as well, with a value of 0 representing its “OFF”state, and 18 representing its “ON” state.

In this experiment, the device was used to puncture silicone tubescontaining water in known pressure. LTH was set to 5 mmHg, UTH to 20mmHg. The time window was set to 100 milliseconds, and the duration ofsolenoid activation was set to 3 seconds.

During the first four punctures, at times ˜5 sec, ˜13 sec, 19 sec, and25 sec, the pressure was ˜36 mmHg, simulating arterial pressure in ahypotensive patient. During the fifth puncture, at time ˜56 sec, thepressure was ˜17 mmHg, simulating venous pressure. Nothing was changedin the device between the punctures.

As seen in the graph, the solenoid was not activated in any of the firstfour punctures into the “artery” tube, despite the measured pressurebriefly passing within the predetermined venous range, both whileincreasing, and while decreasing. However, in the fifth puncture, thistime into the “vein” tube, the solenoid was activated immediately uponend of the time window, because the measured pressure remained withinthe LTH-UTH range.

FIG. 5C is a theoretical graph depicting the concept of using multiplephysiological parameters as inputs for the process described in FIG. 5A,and specifically in step 3008, in order to provide an example of how thesystem may function.

More particularly, FIG. 5C is a graph showing possible real timemeasurements of fluid pressure, PO2 (oxygen tension), and PCO2 (CarbonDioxide tension) at the tip of a needle during puncture of body tissueand blood vessels. The horizontal axis represents time, and the verticalaxis represents the values of the measured parameters (fluid pressure,PO2, PCO2). Additional or other physiological parameters not shown inthis graph may be used, including but not limited to pH, temperature,flow, glucose content, optical reflectance, etc.

Scales on the right side of the graph show possible typical ranges ofeach parameter for venous blood. These may be 5-20 mmHg for fluidpressure, 30-50 mmHg for PO2, 40-54 mmHg for PCO2. These venous rangesare marked by wide bars, to the right of each of the scales. Typicalarterial ranges for these parameters may be approximately above 20 mmHgfor fluid pressure, 75-10 mmHg for PO2, 25 to 45 mmHg for PCO2.

In the graph, the continuous line represents fluid pressure, the dashedline represents PO2, and the dotted line represents PCO2. Depicted aretwo events, A and B, in which parameters change significantly due topuncture of a body lumen or vessel.

Event A represents possible measurements during arterial puncture: fluidpressure may rapidly rise to well above 20 mmHg, PO2 may rise from alevel of ˜25 mmHg in muscle or other tissue to 75-100 mmHg, and PCO2 maydecrease from 30-40 mmHg up to 25 mmHg. Altogether, these values,especially when compared to the values measured in tissue before therapid change at the time of vessel puncture, indicate that the puncturedvessel may be an artery. If the chosen vessel type was a vein, thesystem's CPU may analyze these data and refrain from deploying theblunting element in this vessel. Comparing the values measured duringevent A to the venous ranges (wide bars to the right of the scales)shows that all parameters are outside the venous ranges. Following exitof the needle tip from the vessel, values return to their levels insurrounding tissue.

Event B represents possible measurements during venous puncture: fluidpressure may (less rapidly than before) rise to well 5-20 mmHg, PO2 mayrise from a level of ˜25 mmHg in muscle or other tissue to 30-50 mmHg(significantly less than arterial), and PCO2 may rise from 30-40 mmHg40-52 mmHg. Altogether, these values, especially when compared to thevalues measured in tissue before the rapid change at the time of vesselpuncture, indicate that the punctured vessel may be a vein. If thechosen vessel type was a vein, the system's CPU may analyze these data,recognize the parameters are within the venous ranges (compare values tothe wide bars at the right of each scale), and deploy the bluntingelement in this vessel. Otherwise, following exit of the needle tip fromthe vessel, values return to their levels in surrounding tissue.

FIG. 5D is a simplified theoretical graph depicting various possiblepressure measurement contours, for describing examples of pressurecurves which may be measured at the needle tip of a device 2000, andtheir contour analysis as may be performed by the process described inFIG. 5B. The described curves and analyses are examples, and are notmeant to cover all possible uses of the data within the scope of thecurrent disclosure.

More particularly, FIG. 5D is a simplified, schematic, theoretical graphof fluid pressure (in mmHg) at the needle tip, plotted against time (inseconds). During the first second of measurement, a graph G is shown,depicting pressure which may be measured in tissues such as skin orsubcutaneous tissue, before puncture of a blood vessel. A segment of thepressure curve marked P is shown.

At time 1 second, a theoretical puncture into a vessel occurs. Threepossible graphs are shown from this point: G1—“artifact”—includingsegment Q, G2—“venous puncture”—including segments R, S, T, U, andG3—“arterial puncture”—including segments V, W, X, Y, Z. Of course onlyone such graph may be measured by one device at its needle tip at asingle time, however the three are brought herein together in order toexemplify various possible pressure contours.

Segment P shows pressure slightly fluctuating around 1 mmHg. This may betypical of measurements within body tissue that is not under pressure,i.e. for example skin or subcutaneous tissue, fat, and muscles of thelimbs, without external pressure or edema. Typically pressure in thesetissues may be close to zero, however slight fluctuations as shown insegment P may be common and may result from “noise” caused by movementsof the patient or device, changes in device position and height,electromagnetic interference etc. Various methods of analysis as knownin the art may be used to minimize this “noise” including runningaverages etc.

At second 1 there is an abrupt change in the pressure curve. G1 is anexample of such change, which may be caused not by puncture of a vessel,but for example by extreme movement of the patient. Such an artifact maybe recognized when analyzing the graph, for example by identifying therate of change, which may not be as abrupt, and the contour may not beas smooth, as in the case of true vessel puncture. Typically, such achange may be short standing, and may not reach high pressure levels.

G2 and G3 are graphs describing typical pressure measurements uponpuncture of a vein or an artery, respectively. When puncturing a vein,pressure would typically rise abruptly, however not as abruptly as inthe case of arterial puncture, so the rate of change, as seen by theslope of the graph in segment R (venous), is lower than that in segmentV (arterial). Typically this rate of change in pressure may besufficient to distinguish between venous and arterial puncture, asdescribed in the process of FIG. 5B. Pressure buildup within the needle,fluid passageways, and sensor may take time, typically several tens ofmilliseconds, depending on the vessel pressure, and therefore thepressure graph rises along that period of time. Arterial pressure maytypically be sufficient to reach measured pressure levels above theupper threshold for veins (which may typically be chosen as above 20mmHg), within 100-200 milliseconds from the time of puncture. After thattime, if pressure is still within the venous range, the punctured vesselmay be identified as venous. This is exemplified by segment T which maybe a typical pressure measurement in a central vein, around 15-16 mmHg.This pressure may be relatively high for most patients, however theimportant point is the fluctuations in pressure shown in segment T. Suchfluctuations are typical of venous pressure, and may be caused byreasons as described previously for segment P, and in addition, by thepatient's respiratory activity, and/or cardiac activity. Suchfluctuations typically have a known rhythm, and can therefore beidentified, and may typically not be mistaken for changes in theposition of the needle (i.e. will typically not be assumed to be causedby the needle exiting the vessel or entering an artery).

Even before the pressure graph reaches the venous “stable state”(segment T), segment S shows a significant decrease in the rate ofpressure rise, which can be identified by the process of FIG. 5B,especially when compared to segment R, and considering the time lapsebetween the two segments. In other words, a decrease in the slope of thecurve within a short time, and without a significant rise in absolutepressure, enables predicting the final pressure level, by extrapolation.

In contrast, segment W in graph G3 (arterial) still shows a very steepslope, i.e. pressure continues to rise quickly. The maximal pressureshown in this sample graph as seen in segment X, is very low for anarterial pressure (˜40 mmHg), but may be consistent with a patient inshock, which is an indication for use of the devices of the currentdisclosure. Of note, segment X includes the peak arterial pressure andmay show an abrupt fall in pressure after the peak, which is typical ofan arterial pressure contour. There are various other known features ofthe arterial pressure graph, depending on where the pressure ismeasured, such as the dicrotic notch. However the important point forthe current embodiment is that such abrupt changes as shown in segmentsX and Y of G3 wherein the slope changes from very positive to verynegative or the opposite, are typical of arterial pressure and enabledistinguishing between vessel types. Importantly, these typical contoursmay enable identifying the vessel type within a very short time, e.g.within less than 100 ms, which may advantageously occur before passingof several heart beats of the patient, and before the respectivepulsatile blood pressure contour is recorded. That is to say, waitingthe required time until pulsatile pressure can be identified, may be toolong for optimal function of the cannulation device, and therefore rapididentification (within 50-200 ms) of the vessel type by a short segmentof the contour is beneficial.

At second 2, a theoretical measurement of pressure at a time of exit ofthe needle tip from the vessel lumen is depicted. Both G2 and G3 show anabrupt fall in measured pressure as seen in segments U and Zrespectively. However, due to the large difference in pressure betweenthe lumen and surrounding in the arterial case, and the smallerdifference in the venous case, the slope of pressure decrease is muchsteeper for the artery as seen in segment Z versus the vein as seen insegment U. This steeper slope may enable the system to distinguishbetween exit of the needle tip from an artery as opposed to the typicalpressure fall during diastole (as seen for example at the end of segmentX).

Some or all of the above may be used within the software for analysis ofthe pressure curve contour for identifying the location of a needletip—in tissue, in an artery, or in a vein. Similar considerations andcalculations may be applied to multiple other physiologic parameterswhich may be measured by embodiments of the current disclosure.

Reusable and Disposable Combinations

Various embodiments of reusable and disposable combinations of theelectronic device are described below. These are generally similar tothose described for the mechanical device in FIGS. 2A-2D. Of note, ineach of the following electronic sensor embodiments, the sensor mayeither be disposable or reusable. If the sensor is reusable, there maybe a separation between it and biological fluid, that on the one handallows pressure transmission, and on the other hand prevents sensorcontamination by patients' body fluids. Such a separation may forexample consist of a gel plug, a thin polymeric membrane, or otherappropriate partition.

In an embodiment, the solenoid and trigger mechanism are reusable andthe rest (body, large spring, slider, seal, and passageways) aredisposable. As mentioned above, the sensor may be either disposable orreusable (analogous to FIG. 2A).

In another embodiment, in a device that advances only an external sheath(no guidewire), where there is no seal and possibility of blood entryinto mechanism. Therefore, only the needle, the adapter and/or thesensor are disposable (analogous to FIG. 2B).

In another embodiment, the guidewire may be coaxial with the largespring, but the inner part of the advancement mechanism may bereplaceable. Therefore, only the guidewire, the gripper, the needleadapter, the needle, and/or the sensor may be disposable (analogous toFIG. 2C).

In yet another embodiment, the guidewire is not coaxial with the largespring. Therefore, only the guidewire, the gripper, the needle adapter,the needle, and/or the sensor may be disposable (analogous to FIG. 2D).

Blunting Elements

In some embodiments of the present invention, the cannulation devices ofthe present invention may include blunting elements, which may compriseone or more guidewires, or other elements advanced through the needleand/or a sheath advanced over the needle. In some embodiments, theblunting element may be operable to cover the tip of a needle. In someembodiment, the blunting element may be positioned close to the needletip prior to vessel puncturing, such that the blunting element may bequickly deployed into the vessel to cover the needle tip and preventinjuries to the vessel wall.

An advantage of using a sheath over the needle as the blunting elementof the cannulation device, is that a non-hollow needle can be used. Sucha non-hollow needle may have a relatively small diameter. In addition, aneedle that has a sensor at its tip may be used (usually this will be anon-hollow needle, or hollow but with a small inner diameter). Thesensor may be a pressure sensor or a different type of sensor (flow,impedance, etc.). The sensor may be in electronic communication with thevessel cannulation device and operable to transmit pressure informationto the processor for automatic deployment of the blunting element.

FIGS. 6-11 show various “blunting” elements in accordance withembodiments of the invention.

FIGS. 6A-6D depict an embodiment of a stent like “tip covering” internalblunting element 600. More particularly, FIG. 6A is a 3D depiction ofblunting element 600 having proximal part 604 which may be a guidewireor similar to a guidewire, diverging area 606 which may be an areaconfigured to project forward and outward, then inward, downward, andbackward, converging area 608, which may be configured to projectforward and inwards, distal area 610, gradually becoming softer, anddistal tip 602.

FIG. 6B is a longitudinal section of blunting element 600 in its crimpedstate, inside lumen 6 of needle 2. Needle 2 has distal end 3, lumen 6,and bevel point 7. Blunting element 600 is seen slideably positionedwithin lumen 6 of needle 2, with its distal tip 602 positioned neardistal end 3 of needle 2, not protruding out of lumen 6. Of note, areas606 and 608 of blunting element 600 are flexible and therefore assume arelatively straightened configuration within lumen 6.

FIG. 6C is a longitudinal section of blunting element 600 in itsdeployed state. Blunting element 600 is seen partially protruding out oflumen 6 of needle 2. Area 606 of blunting element 600 may extend forwardand outward out of lumen 6, then backwards inwards and downwards alongand around the outer surface of distal end 3 of needle 2, continued byareas 608 which extend forward and inward, converging into area 610,which may be a guidewire or similar.

FIG. 6D is an isometric depiction of blunting element 600 in itsdeployed state, showing the same features as in FIG. 6C.

In operation, blunting element 600 may be advanced by any of the vesselcannulation devices of the invention, other cannulation devices, ormanually, immediately following puncture of the target lumen. Theblunting element 600 may be advanced to an exact position, such thatareas 606 and 608 cover the inferior aspect of bevel point 7, thuspreventing it from inadvertently puncturing through the vessel wall andexiting the vessel lumen.

In some embodiments, additional struts or wires connect any of proximalpart 604 and diverging area 606 with converging area 608 and distal area610, thus covering also the superior aspect of bevel point 7.

In an embodiment, blunting element 600 may be made of a cable or braid,and areas 606 and 608 consist of a segment of the cable, which may beunwound or uncoiled, and its strands diverge outwards. Other embodimentsof blunting element 600 are possible. The blunting element 600 has anextendable segment (areas 606 and 608) configured to cover bevel point 7in its deployed state, and which in its crimped state, does notsubstantially obstruct needle lumen 6.

In an embodiment, vessel cannulation device 1000 or 2000 may advanceblunting element 600 or any of the following blunting elements (to bedescribed below) to a specific position, then may pull it slightlybackwards (proximally), to make sure areas 606 and 608 cover bevel point7.

FIGS. 7A and 7B depict an embodiment of a coiling “tip covering”blunting element 700. More particularly, FIG. 7A shows a longitudinalsection of blunting element 700 in its crimped state, inside lumen 6 ofneedle 2. Blunting element 700 is seen slideably positioned within lumen6 of needle 2, with its distal tip 702 positioned near distal end 3 ofneedle 2, not protruding out of lumen 6. Area 706 of blunting element700 may be flexible and therefore assume a relatively straightenedconfiguration within lumen 6.

FIG. 7B shows a longitudinal section of blunting element 700 in itsdeployed state. Blunting element 700 is seen partially protruding out oflumen 6 of needle 2. Area 706 of blunting element 700 may extend out oflumen 6, coiling around distal end 3 of needle 2, thus covering bevelpoint 7, and continues as distal part 710, which is a soft relativelyguidewire.

In some embodiments, blunting element 700 may be made of a guidewire,which has been pretreated by heat treatment, mechanical treatment, orother method, to confer a coiling tendency to area 706.

FIGS. 8A-8E depict an embodiment of a “tip completing” blunting element800, shaped as a longitudinally cut tube segment with a shape that fitswith and complements the needle bevel into a blunt end.

More particularly, FIG. 8A shows a 3D depiction of blunting element 800showing distal tip 802, slit 808, inferior fit 806, superior fit 805,and proximal part 804, which may be a guidewire or strip or other longelement, extending proximally from the proximal end of the slit tube,and enabling pushing blunting element 800 distally.

FIG. 8B shows a longitudinal section of blunting element 800 in itscrimped state, inside lumen 6 of needle 2. Blunting element 800 is seenslideably positioned within lumen 6 of needle 2, with its distal tip 802positioned near distal end 3 of needle 2, not protruding out of lumen 6.The blunting element 800, which is longitudinally slit at slit 808, maycoil upon itself such that its ends overlap to some extent, reducing itsouter diameter sufficiently for it to be inserted into lumen 6 of needle2.

FIG. 8C shows a longitudinal section of blunting element 800 in itsdeployed state. Blunting element 800 is seen partially protruding out oflumen 6 of needle 2. Once pushed out of lumen 6 by any of a cannulationdevice or manually, blunting element 800 may pop out to its originalouter diameter, which may be identical or close to that of needle 2.Bevel point 7 may be positioned within inferior fit 806, and superiorfit 805 sits at the upper end of the needle bevel. In this position,blunting element 800 has a distal end 802 which may be round and blunt,while superior fit 805 and inferior fit 806 prevent it from being pushedback proximally. Thus, a blunt needle end may be created.

FIGS. 8D and 8E are 3D drawings showing the same as FIGS. 8B and 8C.

FIGS. 9A-9D depict an embodiment of a “internal sheath” blunting element900, in some embodiments, comprising a thin tube with a blunt,atraumatic tip.

More particularly, FIG. 9A shows a longitudinal section of bluntingelement 900 in its crimped state, inside lumen 6 of needle 2. Bluntingelement 900 is seen slideably positioned within lumen 6 of needle 2,with its distal tip 902 positioned near distal end 3 of needle 2, notprotruding out of lumen 6. Although in this drawing blunting element 900is depicted as a short sheath, it may be a longer sheath with a morerigid proximal part to be positioned at the needle tip when deployed,and a softer distal tip. The change between these areas may be gradual,but may also be in steps. Note also that in this embodiment, bevel point7 of needle 2 may be preferably shaped such that it is at the inner sideof the needle wall, to ensure a smooth taper from blunting element 900.

FIG. 9B shows a longitudinal section of blunting element 900 in itsdeployed state. Blunting element 900 is seen partially protruding out oflumen 6 of needle 2. Once pushed out of lumen 6 by any of a cannulationdevice or manually, blunting element 900 may extend beyond needle distalend 3, and provides a blunt end at distal tip 902 with a smooth taper toneedle 2.

FIGS. 9C and 9D are 3D drawings showing the same as FIGS. 9A and 9B.

FIGS. 10A-10D depict another embodiment of an “internal sheath” bluntingelement 1100, which is different from the previous one in that it coversthe needle bevel point.

More particularly, FIG. 10A shows a longitudinal section of bluntingelement 1100 in its crimped state, inside lumen 6 of needle 2. Bluntingelement 1100 may be seen slideably positioned within lumen 6 of needle2, with its distal tip 1102 positioned near distal end 3 of needle 2,not protruding out of lumen 6. Opening 1106 may be a cross slit in thesheath of blunting element 1100. The sheath may be preshaped with acurve towards the side of the bevel point 7, but the sheath may bestraightened within the needle lumen in this figure.

FIG. 10B shows a longitudinal section of blunting element 1100 in itsdeployed state. Blunting element 1100 is seen partially protruding outof lumen 6 of needle 2. Once pushed out of lumen 6 by any of acannulation device or manually, blunting element 900 may extend beyondneedle distal end 3, and provides a blunt end at distal tip 1102 withinthe vessel lumen. Additionally, the blunting element 900 may curvetowards bevel point 7, and is may be pulled slightly backwards such thatbevel point 7 enters into opening 1006, thus rendering the needle tipblunt.

FIG. 10C shows a 3D drawing of deployed blunting element 1100 withoutthe needle.

FIG. 10D shows a 3D drawing of deployed blunting element 1100 with theneedle.

FIGS. 11A-11D depict an embodiment of a “sandwich sheath” bluntingelement 1200, may comprise two layers of over-the-needle sheaths.

More particularly, FIG. 11A shows a longitudinal section of bluntingelement 1200 in its crimped state, positioned over needle 2. Bluntingelement 1200 may comprise outer sheath 1202 and inner sheath 1204. Innersheath 1204 may have inner sheath distal tip 1206 and inner sheathprotrusions 1208. Outer sheath 1202 may have distal tip 1210. Theproximal end of outer sheath 1202 may be connected to needle hub 5, andmay have slots through which protrude protrusions 1208. Inner sheath1204 may be slideably positioned between needle 2 and outer sheath 1202.The distal tips 1206 and 1210 of both inner sheath 1204 and outer sheath1202 may be proximate to each other and together create a taper towardsdistal end 3 of needle 2.

FIG. 11B shows a longitudinal section of blunting element 1200 in itsdeployed state. Inner sheath 1204 is seen partially protruding beyonddistal end 3 of needle 2, providing a blunt end covering bevel point 7at distal end 3. Although in this drawing inner sheath 1204 is depictedas protruding a short distance, it may protrude to a large distance, insome embodiments, with a more rigid proximal part to be positioned atthe needle tip when deployed, and a softer distal tip. The changebetween these areas may be gradual, but can be in steps.

In use, once the vessel is penetrated by needle 2, inner sheathprotrusions 1208 may be pushed forward by a cannulation device or auser. Inner sheath 1204 slides over needle 2 and within outer sheath1202 at least until it covers distal tip 3. An advantage of thisembodiment is that inner sheath 1204 has almost no contact with tissuesurrounding the needle, and so can be advanced without pushing theneedle out of the vessel, as can commonly happen with sheaths overneedles. At the same time it does not compromise the needle inner lumen.

Any of the blunting elements and cannulation devices described hereinand in the incorporated applications may be used interchangeably witheach other.

Guidance

Various embodiments for guiding the puncture procedure are describedbelow. The descriptions will use device 1000 as example, but may relateto any of devices 2000 or others described above and elsewhere.

Mechanical Guidance

In an embodiment shown in FIG. 12A, a simple linear mechanical guide1300 may be used for guiding the cannulation procedure. Mechanical guide1300 enables sliding any of the above described cannulation devices overa slope of approximately 30-45 degrees, directed at the target vessel(marked “A” in the figure), while remaining substantially parallel tothe vessel's longitudinal axis. Optionally, mechanical guide 1300 may befoldable. Markings at its front edge may be used to indicate distancebetween punctures.

In use, mechanical guide 1300 may be placed on the patient's skin, withits central marking above the estimated location of the target vessel,and pointing in the direction of the vessel's longitudinal axis. Theuser may begin puncturing the skin at a location approximately 1-2 cm toone side of the center marking, and performs consecutive parallelpunctures, each time approximately 2 mm closer to the central marking,and continues beyond it if necessary.

In this manner, all possible space where the target vessel can pass maybe covered, and once the vessel is punctured by the needle, thecannulation device may be deployed.

In an embodiment shown in FIG. 12B, a simple rotary mechanical guide1350 is used for guiding the cannulation procedure. Mechanical guide1350 may enable sliding any of the above described cannulation devicesover a slope of approximately 30-45 degrees to the patient's skin, whilerotating the needle tip at the same point, in some embodiments, 1-2 mmbelow the skin surface. Optionally, mechanical guide 1350 may befoldable. Optionally, a surface 1351 may slide up and down the slope andcan be locked to it at any point. An arch 1352 may be attached tosurface 1351, with its center located beyond the lower edge of surface1351. Attachment 1353 may slide around arch 1352, while slab 1354 mayslide back and forth over attachment 1353. Device 1000 may be attachedto slab 1354 such that it can be moved around arch 1352 and back andforth with its needle 2 pointing to the center of arch 1352. Markingsalong arch 1352 may be used to indicate angles between punctures.

In use, mechanical rotary guide 1350 may be placed on the patient'sskin, with its central marking above the estimated location of thetarget vessel, and pointing in the direction of the vessel'slongitudinal axis. Optionally, the user may determine the height ofsurface 1351 such that the center of arch 1352 is at any depth below thepatient's skin surface, in come embodiments, 1-2 mm below the skin.Alternatively, this height may be fixed. The user may begin puncturingthe skin at an angle approximately 30-45 degrees to one side of thecenter marking, and perform consecutive punctures, each time going a fewdegrees closer to the central marking, and continues beyond it ifnecessary.

In this manner, most possible space where the target vessel can pass maybe covered, and once the vessel is punctured by the needle, thecannulation device will deploy.

Optionally, stops may be placed that limit sliding of slab 1354,limiting the minimum and maximum needle insertion depths, so that theneedle is not accidentally pulled out of the skin, and remains insidethe skin.

Imaging Based Guidance

In some embodiments, imaging may be used as part of any of thepreviously described cannulation devices.

In some embodiments described in FIGS. 13A-13D, an ultrasound transducer1400 may be slideably located at the tip of needle 2 of device 1000.More particularly, FIG. 13A is a simplified 3D drawing of device 1000with needle 2, transducer 1400 around the tip of needle 2, arm 1401connected to transducer 1400, and slideably connected to connector 1402.FIG. 13B shows transducer 1400 made of two parts, which can be separatedto remove it off needle 2 or a sheath that may have been placed over theneedle. This may allow the needle or the needle/sheath to be removed orreplaced. FIGS. 13C and 13D are simplified side views of device 1000with a longitudinal section of the tissue. FIG. 13C shows device 1000before skin puncture, and FIG. 13D shows device 1000 with needle tip inthe target vessel, and a deployed guidewire in the blood vessel.Although described above as being made of two parts, transducer 1400 maybe made of more than two parts, or alternatively of one part furthercomprising a longitudinal slit, such that it may be positioned with theneedle at its center, slid over the needle during puncture, and easilyremoved following puncture.

In an embodiment, transducer 1400 is a Doppler ultrasound transducerwith a narrow beam, which provides an audio or visual indication of theintensity of the sensed Doppler signal. The user may place transducer1400 at the desired puncture site, and may tilt device 1000 in varyingangles until he identifies the angle with the strongest signal,indicating the direction of the target vessel. The user then puncturesthrough the skin until device 1000 deploys.

In an embodiment shown in FIG. 14, a guidance system 1500 is providedwhich includes the device described previously in FIGS. 13A-13D, asurface or mat 1501 on which are mounted one or more position sensors1502, connected to a processor 1503, which is connected to indicator1504. Position sensors 1502 may for example measure angles α and β ofdevice 1000 in relation to mat 1501. The distal end of transducer 1400may be connected or secured to mat 1501 at a certain point such that itcan pivot but not move in relation to mat 1501.

In use, the user may change the angles α and β of device 1000 relativeto mat 1501 by moving it from side to side, and forward and backward.During this movement, processor 1503 may register the position of device1000 together with the corresponding signal measured by transducer 1400at each position. Processor 1503 may then analyze the data to find theposition in which the maximal signal is sensed. Processor 1503 can theneither turn the indicator on (light, sound, or vibration) when thatposition is reached by the user, or it can use two or more indicators toguide the user to the correct position or angle (e.g. by directing himto move right, left, up or down).

In an embodiment, transducer 1400 may be a 3D ultrasound probe. An imageof the 3D space imaged by the probe may be displayed on a screen, whichmay be part of device 1000 or separate from it. This image may be aholographic image, a 2D perspective view of the imaged 3D space, or anycombination of cross sectional views derived from the 3D model. Thereconstructed screen image may be created as if from the point of viewof the user, the needle, or from any other angle.

In an embodiment described in FIGS. 15A and 15B, a device 4000 maycomprise cannulation device 1000, transducer 1400, screen 4001, a spring4002, a handle 4003, and a trigger 4004. Device 1000 may be slideablypositioned within device 4000 with spring 4002 pushing it forward.Spring 4002 may be replaced by any other mechanism to push device 1000forward, such as a motor or solenoid. Device 1000 can be abruptlyadvanced upon pulling trigger 4004 by the user.

In this embodiment, the imaging system provides an indication on screen4001, showing where the needle will reach at the end of its travel.

The user may decide when the indication is correctly positioned withinthe vessel lumen, and pulls the trigger. Device 1000 may advance anddeploy once needle 2 penetrates the blood vessel.

Robotic Systems

Device 1000 may be used in a robotic system to automatically detect thetargeted blood vessel and deploy the needle, guidewire, and/or otherblunting elements into the targeted blood vessel.

In an embodiment shown in FIG. 16, a system 5000 may include imagingmeans, as well as means for automatically changing the orientation ofdevice 1000, and for advancing device 1000. More specifically, FIG. 16is a schematic 3D drawing showing system 5000 comprising device 1000slideably disposed within case 5001, while being pushed forward by pushelement 5002, as well as needle 2 and transducer 1400, which ispivotally connected to mat 5003, optionally using pivot element 5008. Onmat 5003 are sensors 5004, and strip 5005. A linear motor 5007 may slideover strip 5005, and over another strip 5006 which is pivotallyconnected to case 5001. A CPU 5010 located on mat 5003, may be connectedto sensors 5004, device 1000, transducer 1400, and linear motor 5007.Push element 5002 may be an electrical motor, linear or rotary, asolenoid, or a spring with a “brake” controlling the extent of itsadvancement.

In use, the system may be placed over a patient's skin, in the vicinityof a target vessel. Initially the system may perform scanning bymeasuring the Doppler signal returned to transducer 1400 while changingthe angle of device 1000 relative to the skin to identify the angletowards the target vessel. This may be done by linear motor 5007 slidingover strip 5005 which may change angle δ, and by sliding strip 5006through linear motor 5007 which changes angle γ. In some embodiments,angle γ is kept constant while angle may change over its complete range,then angle γ may change slightly, and the scanning may repeat over angleδ, and so on.

The Doppler signal measured by transducer 1400, may be recorded by CPU5010 for each device position. Once the angle at which the signal ismaximal is identified, the system may return case 5001 to that angle,and advance device 1000 straight into the patient's skin, until thedevice deploys. Device 1000 may send a signal to CPU 5010 indicatingthat deployment occurred, and CPU 5010 may immediately stop advancementof device 1000.

Alternatively or additionally, the indication of deployment from device1000 to CPU 5010 may prompt slight elevation of the needle tip anddecrease of its angle with the vessel's long axis, thus moving theneedle tip away from the distal vessel wall, and bringing the blunt sideof the needle bevel closer to the proximal vessel wall.

The system may then cease its operation and let the user continue fromthere, or alternatively it may automatically advance a sheath into thevessel, or draw blood from the blunted needle.

The system may be able to distinguish between a maximal arterial signaland a maximal venous signal, and choose the maximal signal according tothe user's preference of an arterial or venous target vessel.

In an embodiment, a vessel cannulation system may comprise a 3D imagingsystem, a robotic arm, and device 1000. The imaging system may scan thetarget area using an ultrasound probe and creates a 3D model of thevessels in it. The vessel cannulation system may choose the targetvessel according to the user's preference of arterial vs venous. Incontrast with other previously described robotic systems, thecannulation system may then advance the needle abruptly to the exactlocation of the vessel lumen, at a high acceleration and speed with theaim of puncturing the vessel within 50-200 ms of the beginning ofmovement towards the vessel, before the vessel has a chance to move, asoften happens when the puncture takes a longer time. Optionally, thepuncture process is divided into two phases, the first is skin puncture,and the second is vessel puncture, with an optional brief pause inmovement between the two phases. In this case, the time mentioned aboveis measured from the second motion, when movement towards the vesselbegins following the pause after the skin was penetrated. Optionally,the advancement mechanism is configured not to exceed a certain force,so that if device 1000 deploys before the estimated distance, the needlewill not exert excessive force on the guidewire in the vessel.

Any of the above described devices may optionally additionally comprisemeans for identifying the authenticity and/or validity of disposablecomponents used with it. Such means may for example include an RFID orbarcode reader on the capital equipment unit, and an RFID chip orbarcode on the disposable unit. If the disposable is found invalid orexpired, the capital equipment unit will be rendered unusable, and willnot become usable again until a disposable with an authentic non-expireddisposable is presented to the reader.

Expandable Sheath

Expandable sheaths that are known in the art suffer from variousshortcomings. For example, some sheaths described in the art have rigidlongitudinal beams connected by an elastic material. In such sheaths,the expansion of the sheath may occur between a specific pair of beamsinstead of homogenously between all beams. In some sheaths, the dilator,or catheter placed to expand the sheath, could exit via the side of thesheath. Also, some such sheaths would buckle and collapse upon removalof the catheter from within their lumen. Manufacturing cost forexpandable sheaths having a complex structure may also be high.

The expandable sheaths of embodiments of the present invention mayovercome these shortcomings. In particular, the expandable sheath ofembodiments of the present invention may provide axial rigidity,resistance to buckling, radial expandability, homogenous expansionaround the sheath, improved sealing, and are manufactured in a muchlower cost. In some embodiments of the present invention, the expandablesheath may be used in combination with cannulation devices of theinvention. In fact, the expandable sheath and cannulation device maycomplement each other and may be considered a system for vascularaccess. For example, the expandable sheath may be attached to the distalend of device 1000, covering the needle, which may be attached to lueradapter 11. After puncture of the vessel by the needle, automaticdeployment of the guidewire, and insertion of the sheath into thevessel, the needle and guidewire may be removed from within the sheathshaft, leaving the expandable sheath in the vessel. In otherembodiments, a rigid large diameter sheath may be used in conjunctionwith the expandable sheath. For example, the rigid large diameter sheathmay be fitted with a mandrel, where the rigid large diameter sheath maybe inserted into the expandable sheath to further expand the expandablesheath.

Spiral Connections

FIG. 17 shows an embodiment of expandable sheath 6000 with spiralconnections between the beams. More specifically, FIG. 17 is asimplified 3D depiction of the distal part of a single layer ofexpandable sheath 6000 comprising three beams 6001 separated by slits6002. Connections 6003 may bridge between beams 6001, and may bearranged in a spiral around sheath 6000 as demonstrated by arrow 6004.In some embodiments, at the tip of the sheath, all beams are connectedat the same level. Optionally, also near the sheath hub, at the level ofthe transition from the hub diameter to the needle diameter, there couldbe a connection between all beams at the same level.

The layer shown in FIG. 17 can be made of a relatively rigid materialsuch as nylon or PTFE, while an additional, elastic layer, made ofsilicone, latex, polyurethane or other elastomer may be added to therigid layer. The elastic layer may be either on the external, theinternal or on both sides of the rigid layer. The spiral arrangement mayprevent buckling of the sheath during insertion, and at the same timeprevents dilation from occurring only between one pair of beams, as mayhappen when all connections are made at the same levels.

Manufacturing this sheath may be done for example by laser cutting thepattern of slits shown in FIG. 17 into the rigid layer, sparing theconnections. This layer can then be post processed for making the taperat the tip and flare at the hub, and then dipped to add the elasticlayer. Alternatively this sheath may be manufactured by micro molding.

Outer Support

In an alternative embodiment, the beams are not inter-connected.Instead, external support may be provided during insertion into thetissue, to that part of the sheath which is outside the skin, thuspreventing its buckling. This may be done for example by a ballooninflated around the sheath, a highly viscous pad, or a telescopic orpeelable element, which may remain outside the body during insertion. Inan alternative embodiment, the beams are not inter-connected. Instead,external support may be provided during insertion into the tissue, tothat part of the sheath which is outside the skin, thus preventing itsbuckling. This may be done for example by a balloon inflated around thesheath, a highly viscous pad, or a telescopic or peelable element, whichremains outside the body during insertion.

Rigid and Elastic Layers Forces

The force required to expand the rigid layer may be determined by thelayer material, thickness, number and width of beams, distance betweenthe connections, and the connections dimensions. This force shouldoptimally be as small as possible, but high enough to prevent beams fromdisconnecting due to axial load during insertion into tissue.

The force required to expand the elastic layer may be determined by itsmaterial and thickness. This force may optimally be high enough toprevent a dilator/catheter from exiting through the side of the sheath.

Inner Sheath

In an embodiment, initial expansion of the sheath may be done byinsertion of a rigid inner sheath with an outer diameter equal to theinternal diameter of the expanded sheath, and the maximal possibleinternal diameter.

This internal sheath may be inserted over a rigid dilator, which maythen be removed. This internal sheath may additionally have a valve orconnector at its proximal end to serve as the valve or connector of thedilated sheath.

Using such an internal sheath may ensure that the expandable sheath doesnot buckle during removal of catheters or tools from it.

Overlapping Sheath Hub and Needle Hub

In an embodiment shown in FIG. 18, an expandable sheath 6100 isdescribed, in which the sheath hub overlaps with the needle hub. Morespecifically, FIG. 18 is a schematic longitudinal cross section throughsheath 6100 comprising sheath shaft 6101, sheath valve 6102, and sheathhub 6103. Needle 2 is shown having needle hub 6110. Overlapping of thehubs may enable keeping the overall needle 2 length shorter whilemaximizing the sheath shaft length.

Needle hub 6110 may have a mechanism for locking it to cannulationdevice 1000, such as a luer lock or a snap connector. Sheath hub 6110may have the same. Alternatively both hubs may separately lock ontocannulation device 1000, or may have a connection (snap or lock) betweenthem, while only one of them locks to cannulation device 1000.

Sheath Valve

Hemostatic valves in large diameter sheaths usually have a complexstructure due to a requirement on the one hand to provide sufficientsupport that may withstand blood pressure over a large valve surfacearea, and on the other hand may be able to compress and allow a largebore tool or catheter to pass through them.

In this embodiment, a valve 6102 shaped as a ring, a toroid, or a spherewith a central hole may be used in the expandable sheath. This valve maybe placed within the hub 6103 but may be connected such that when pushedby a tool or catheter, it may protrude partially or fully into theexpandable area, where there is more space for it, and therefore it doesnot require a complex structure, and is cheaper to manufacture. Theforce applied by the valve against the expandable sheath shaft can alsoaid in the initial expanding of the sheath.

Pull Sheath Design

In yet another embodiment shown in FIG. 19, an expandable sheath 6200 isshown, which is based on pulling instead of pushing during insertion.

More specifically, FIG. 19 is a schematic longitudinal cross section ofsheath 6200 comprising outer sheath shaft 6201 having distal tip 6202and step 6203. Inner sheath 6204 consists of distal tip 6205, bulb 6206,and shoulder 6207. Bulb 6206 is configured to be collapsible, forexample by splitting it longitudinally and removing some of itsmaterial. Step 6203 of outer sheath 6201 is configured to engage withshoulder 6207 of inner sheath 6204.

Sheath shaft 6201 may be made of at least two layers as described abovefor the embodiment in FIG. 17, but does not require high axial rigidityand therefore does not require the connections between beams. Althoughless optimal, it can even be optionally made of just one expandablelayer, but must not be longitudinally stretchable.

Inner sheath 6204 may be made of a rigid or semi rigid polymer such asnylon or PTFE, or a metal such as SS. Optionally inner sheath 6204 maybe an integral part of needle 2. In some embodiments, needle 2 may havestep 6203 as part of the needle itself.

In use, all the above elements may be used as one to penetrate a lumen.Since step 6203 is engaged with shoulder 6207, distal tip 6202 of sheath6200 may be pulled into the tissue by needle 2 and inner sheath 6204,both rigid structures, instead of sheath 6200 being pushed into thetissue from its proximal end (i.e. from its hub end). Stateddifferently, in other embodiments, because the sheath is not connectedto the distal end of the needle, it must have sufficient axial rigidityto resist friction, and not collapse when inserted into the tissues,such as skin, subcutaneous fat, fasciae, etc., which may be in the wayof penetrating a vessel. In an embodiment, step 6203 of outer sheath6201 is being pulled forward (into the tissue) by shoulder 6207 of inner(rigid) sheath 6204 (or needle 2, if it is integral to the inner sheathas described above), so that the rigid inner structure 6204 or rigidneedle shaft takes up all the axial load. Therefore, the sheath 6200 maynot buckle when inserted.

Once inside a lumen, needle 2 may be removed, allowing bulb 6206 tocollapse towards its center, which makes removal of inner sheath 6204easy. After removing inner sheath 6204, a dilator or catheter, or alarge bore rigid inner sheath may be inserted into expandable sheath6200 to expand it.

External Sheath

In an embodiment shown in FIG. 20, an additional external sheath may beused to provide support to the expandable sheath during insertion intothe tissue, in order to prevent it from buckling, without the need forcreating connections between the beams.

More particularly, FIG. 20 is a schematic 3D depiction of sheath 6300consisting of expandable sheath 6301, and external sheath 6310.

Expandable sheath 6301 is similar to expandable sheaths described above,in that it may be made of one or two layers, which may be radiallyexpandable and have a degree of axial rigidity. However expandablesheath 6301 does not need to have a high degree of axial rigidity, andtherefore may for example comprise several beams without any connectionsbetween them. Expandable sheath 6301 has a tapered distal tip 6302, anda proximal end 6303, which is flared and connects to hub 6304.

External sheath 6310 may have distal tip 6311, proximal end 6312, handle6313, an optionally distal connection 6314 and proximal connection 6315.An optional support element 6316 may connect proximal end 6312 ofexternal sheath 6310 to hub 6304.

External sheath 6310 may be an elongate sheath with at least onelongitudinal slit, which may be bridged by connections 6314 and 6315.

In use, sheath 6300 may be inserted over a needle into the tissue priorto entering into the vessel. Support element 6316 may prevent sheath6310 from sliding over expandable sheath 6301. Once in a lumen, supportelement 6316 may be removed by pulling it, and external sheath 6310 maybe pulled backwards at handle 6313, tearing at connections 6315 and6314. The needle may then be removed, and expandable sheath 6301 may beready to be expanded in the tissue.

Tear-Away Option

Any of the above described sheaths may optionally additionally betearable, such that after placement of a catheter through suchexpandable sheath, the sheath may be torn and removed, leaving thecatheter in the vessel. In some embodiments, the tearable shafts aremade using tubes with a wall thickness between 0.01 mm to 0.3 mm,between 0.05 to 0.2 mm, between 0.1 to 0.15 mm. In some embodiments, thewall is less than 0.15 mm, less than 0.1 mm, less than 0.05 mm, or lessthan 0.01 mm.

Various additional embodiments for improved expandable sheaths aredescribed in FIGS. 21-24. These embodiments may be made of a single,typically inelastic material, and may provide increased axial strengthwhile keeping total wall thickness low and minimizing manufacturingcosts. Such materials may include polytetrafluoroethylene (PTFE),polyether block amid (PEBAX), polyether ether ketone (PEEK),polypropylene, etc. When referring to inelastic, it is meant that anyexpansion of the sheaths described in FIGS. 21-24 may be achieved by achange in their conformation, or in other words by unfolding, ratherthan by stretch of their material as was described for embodiments inFIGS. 17-20.

FIGS. 21A-B depict a sheath 6400 made of a longitudinally cut tube 6410which may be folded spirally along the longitudinal cut.

More particularly, FIG. 21A is a 3D schematic depiction of tube 6410from which sheath 6400 may be made. Tube 6410 may be made of aninelastic polymer, which also has some shape memory, such aspolypropylene. For example, for the purpose of being inserted over an18G needle and being expandable to 14 fr, an appropriate tube may havean internal diameter of 4.6 mm and a wall thickness of 0.05 mm or less.A longitudinal slit 6420 may be made along the longitudinal axis of tube6410, sparing the hub region. This longitudinal cut may be pre-cutduring manufacturing or a perforated line that may be torn apart by theuser prior to being inserted over a needle. Tube 6410 may preferably bean inelastic layer made with inelastic polymers such aspolytetrafluoroethylene (PTFE), polyether block amid (PEBAX), polyetherether ketone (PEEK), polypropylene, etc.

FIG. 21B shows external sheath 6400 spirally folded over needle 2 toreach an inner diameter closely fit to the outer diameter of the needle.The two sides of cut 6420 may overlap and each side of slit 6420 tocreate a spiral around needle 2.

In some embodiments, tube 6410 may be dipped in an elastic material suchas polyurethane or silicone to create an elastic outer layer. This maycreate a smoother outer surface, and enable sheath 6400 to expand whilemaintaining fluid seal along the sheath. As such, this process maycreate an expandable sheath. Alternatively, such an elastic outer layermay be manufactured by sliding an elastic tube over tube 6410, shrinkinga heat shrinkable tube over it, or by other methods known in the art.When expanded, sheath 6400 may return to its initial diameter as in FIG.21A. Therefore, in operation, after the insertion of the expandablesheath and needle into a vessel, the needle may be removed, allowing theexpandable sheath 6400 to expand and accommodate intravascular devices,such as central catheters, balloon catheters, etc.

In another embodiment, shown in FIGS. 22-24, longitudinal corrugationsmay be used in the tube to create a sheath with high axial strength.

The corrugations of the present invention may be of various number,size, and shape, from multiple micro-corrugations, to a single largecorrugation or fold.

FIGS. 22A-22D depict a sheath with multiple micro-corrugations inaccordance with embodiments of the present invention.

More particularly, FIG. 22A is a 3D depiction of tube 6510 from whichexpandable sheath 6500 (not shown) is made.

FIG. 22B is a transverse cross section of tube 6510, in which ID1 is theinternal diameter of tube 6510 in its crimped state, which in someembodiments may be in a close fit to the outer diameter of the needle.In some embodiments, ID1 of tube 6510 in its crimped state may bebetween 0.3 mm to 3 mm, preferably between 0.5 mm to 1.5 mm. Forexample, FIG. 22B shows an ID1 of ˜1.3 mm. In some embodiments, theexpanded internal diameter of the sheath may be between 1 mm to 7 mm,preferably between 2 mm to 5 mm. For example, FIG. 22B shows a tubecapable of expanding to achieve an internal diameter of 4.6 mm. Theinternal diameter of the tube may vary depending on the gauge of theneedle and the application for which it is used.

As shown in FIG. 22B, OD1 is the outer diameter of tube 6510 in itscrimped state. In some embodiments, the OD1 of tube 6510 in its crimpedstate may be between 0.5 mm to 4 mm, preferably between 0.7 mm to 2.0mm. For example, FIG. 22B shows tube 6510 having an OD1 of ˜1.9 mm. Insome embodiments, the expanded outer diameter of the sheath may bebetween 1.2 mm to 7.5 mm, preferably between 2 mm to 5 mm. The expandeddiameter of the tube may vary depending on the object (catheter) thatmay be inserted within it.

Angle θ is the angle around the circumference of tube 6510 occupied byeach individual corrugation. In some embodiments, Angle θ is between 5degrees to 30 degrees, between 12 degrees to 25 degrees, or between 15degrees to 20 degrees. For example, in the case shown in FIGS. 22A-CAngle θ is 15 degrees, as there are 24 corrugations in total.

FIG. 22C is an enlarged view of detail A from FIG. 22B, showing angle coformed between the two strips of tube around a single corrugation. R1 isthe radius of this fold, which may be 0.01 mm-0.5 mm. R2 is the radiusof the fold between two corrugations, may be 0.01 mm-0.5 mm. R1 and R2may be equal or different.

FIG. 22D is a schematic depiction of a segment of a crimped tube 6510,showing total crimped wall thickness “a”, gap between two adjacentcorrugations “b”, and tube 6510 wall thickness “c”.

In some embodiments, “a” may be between 0.1 mm and 0.4 mm, “b” may bebetween 0.01 mm and 0.5 mm, and “c” may be between 0.01 mm and 0.2 mm,preferably 0.02 mm to 0.05 mm.

To attain a desired ratio of sheath expansion “t” while maintaining adefined total wall thickness, each cross sectional segment of thenon-expanded sheath may be able to lengthen by the desired ratio ofexpansion. Therefore each cross sectional segment of the crimped tube,equal to the total crimped wall thickness “a”, may contain a length oftube wall equal to “a” times “t”, in the expanded state.

In a case shown in FIG. 22D, the expansion ratio may be *3, as thefolded sheath has a total thickness “a” of 0.3 mm, and each crosssectional segment 0.3 mm long may contain three folds of sheath, thatcan open to a total length of ˜0.9 mm. This may be based on a tube wallthickness “c” of 0.05 mm, and gaps “b” of the same width between thefolds.

Manufacturing of tube 6510 may be by extrusion. The sheath may either beextruded expanded, optionally with larger diameter folds at radii R1 andR2, then crimped or folded. Alternatively, tube 6510 may be extruded inits completely crimped state.

In another embodiment, FIGS. 23A-23C depict sheath 6600, which haslarger and different type of corrugations. For example, FIG. 23A shows afolded tube 6610 with 4 corrugations.

More particularly, FIG. 23A is a 3D depiction of sheath 6600, showingneedle 2, folded tube 6610, and taper 6620. The folding of tube 6610creates a large “step” at the distal end of the tube, which necessitatescreating a taper. This can be done for example by heat treatment of thedistal tip of tube 6610, or by adding an elastic material to the end ofthe tube.

FIG. 23B is a cross section of crimped tube 6610, around needle 2.

FIG. 23C is a 3D depiction of tube 6610 before being folded into itscrimped state. Tube 6610 can be manufactured already having thecorrugations, its proximal end can then be flared to fit a hub, and therest of its length may be crimped based on the extruded folds. As shownin FIG. 23B, the large corrugations are folded around needle 2, tocreate a low profile structure.

In another embodiment, FIGS. 24A-24G depict sheath 6700, which has asingle longitudinal corrugation.

More particularly, FIG. 24A is a 3D depiction of sheath 6700 in itscrimped state, over needle 2. The expanded detail in the figure is thesheath's distal tip, in which particular attention is given to creationof a smooth taper, as will be detailed below.

FIG. 24B is a 3D depiction of sheath 6700 in its expanded state.Although in some embodiments, needle 2 will not be inside sheath 6700 atthis stage, it is shown as reference so that the change in sheathdiameter can be appreciated.

FIG. 24C is a schematic cross sectional view of crimped tube 6710 ofsheath 6700 at around mid-distance between the sheath's hub to its tip.

A cross section of needle 2 is seen as a circle, surrounded by tube6710, which is folded/rolled around needle 2, creating a first singlelayered loop around needle 2, and then continues twisting around theneedle as a double layer. In some embodiments, the double layer maysurround the needle for approximately one additional complete turn.

FIG. 24D is another depiction of the embodiment, a schematic drawing ofthe same cross section, in which tube 6710 is less tightly folded/rolledaround needle 2, so that the layers are more clearly seen.

FIGS. 24E and 24F show additional details of the structure of a possibleembodiment of sheath 6700.

FIG. 24E is a schematic 3D depiction of tube 6710, with one of its sidesfolded into a single layered cylinder with an internal diameter p, witha tight fit to needle 2. The remainder of the circumference of tube 6710is folded so that its two layers are adjacent each other, to a length ofq.

A dashed line 6720 denotes an optional trimming line of the end of tube6710. Angle Ω may be the angle between line 6720 and the straight end oftube 6710.

Angle Ω may be between 0-45 degrees, preferably 5 to 30 degrees.

FIG. 24F shows the same tube 6710, in which the tube end was trimmed atline 6720, and wherein an additional trim was performed to shorten oneof the layers of tube 6710 at line 6730, which may be parallel to line6720, but may be at an angle to it. This additional trim may create agap at a distance r between the ends of the two layers, so that asmoother taper can be created, as will be shown in FIG. 24G. Thedouble-layered fold of tube 6710 is folded around the needle in thedirection of the arrow, so that line 6720 spirals around the previoussingle layered fold.

FIG. 24G is a 3D depiction of the distal end of tube 6710 of sheath6700. The taper created by the trimmed distal end of tube 6710 is seen.Using heat treatment, adhesive, or other method, the ends of the foldedtube 6710 may be tightened around the needle. The longer end along line6720 may cover the shorter end along line 6730, aiding in creation ofthe taper. The free folded end of tube 6710 is parallel to the long axisof needle 2 and tube 6710, creating line 6740.

As mentioned above, the procedures performed using the devices of theinvention may range from placement of central lines of various types(venous or arterial), through placement of smaller, peripherallyinserted venous or arterial cannulae, to short term cannulation of avessel or lumen (without leaving an indwelling catheter) for samplingbody fluids, monitoring, or delivering substances.

Following is a description of specific features of embodiments enablingeach of these.

Central Catheter Placement (CVC, PICC, Midline Etc.)

a. Over Guidewire—Traditional Technique

In an embodiment, the minimal capability of the cannulation device maybe utilized. A vessel cannulation device 1000 (or other) may be used forplacing a guidewire only in a vessel lumen. A catheter with a dilatormay then be inserted over the guidewire.

b. Through Expandable Sheath

In an embodiment, the full capability of the cannulation device may beutilized. A vessel cannulation device 1000 (or other) may be used forplacing a guidewire in a vessel lumen. An expandable sheath which hasbeen on the needle may be inserted into the vessel lumen over the needleand guidewire. The expandable sheath may be fitted over the needle priorto both being attached to the vessel cannulation device. After insertioninto the vessel lumen, the cannulation device, the needle and theguidewire may be removed, leaving only the expandable sheath in thevessel. A catheter with or without a dilator is then inserted throughthe expandable sheath. Optionally, the expandable sheath may be tornaway and removed if the catheter is to be left in place for a long timeperiod.

c. Rapid Exchange Over Needle

In an embodiment, a catheter 6800 having a side opening in a “rapidexchange” fashion is placed over the needle 2 of vessel cannulationdevice 1000, as shown in FIG. 25. Once the device deploys in the lumen,central catheter 6800 is slid into the vessel lumen over the needle, andthe needle and guidewire are removed with the cannulation device. Insome embodiments, the sliding of catheter 6800 over the needle may beperformed manually. Optionally, catheter 6800 may be insertedautomatically by device 1000.

Optionally, a support element (not shown), consisting of a short rod,tube, or any other structure, may temporarily connect between the distalpart of catheter 6800, and the proximal end of needle 2, its hub, ordevice 1000 (similar to support element 6316 of sheath 6300 in FIG. 20).This support element may assist in insertion of the needle and catheterthrough the tissues, preventing the catheter from being pushed backwardsby friction with the tissues. Once catheter 6800 is in the vessel, thesupport element may be removed.

Peripheral IV Catheter Placement

When inserting a peripheral IV catheter, in some embodiments, thecatheter may be pre-mounted over the cannulation device needle.Insertion can follow deployment any of the above described bluntingmechanisms. Insertion may be manual, following the deployment, or may atleast partially be performed automatically by the vessel cannulationdevice, as previously described, and may occur after or simultaneouslywith the automatic blunting element advancement.

Short Term Cannulation/Blood Sampling

In another embodiment, after the needle was blunted by any of the abovemethods, a port in the needle hub, or a port in the vessel cannulationdevice (in its needle adapter or in its body), can be used as a point ofaccess to the vascular system, for blood drawing, drug or fluidadministration, or monitoring.

Although described herein in the context of vascular cannulation, thedevices and methods of the current invention may be used beneficiallyfor cannulating any other body lumen.

Computer System

The term “computer” is intended to have a broad meaning that may be usedin computing devices such as, e.g., but not limited to, standalone orclient or server devices. The computer system may include, e.g., but isnot limited to, a main memory, random access memory (RAM), and asecondary memory, etc. Main memory, random access memory (RAM), and asecondary memory, etc., may be a computer-readable medium (e.g., anon-transitory computer readable storage medium) that may be configuredto store instructions configured to implement one or more embodimentsand may comprise a random-access memory (RAM) that may include RAMdevices, such as Dynamic RAM (DRAM) devices, flash memory devices,Static RAM (SRAM) devices, etc.

The computer may also include an input device may include any mechanismor combination of mechanisms that may permit information to be inputinto the computer system from, e.g., a user. The input device mayinclude logic configured to receive information for the computer systemfrom, e.g. a user. Examples of the input device may include, e.g., butnot limited to, a mouse, pen-based pointing device, or other pointingdevice such as a digitizer, a touch sensitive display device, and/or akeyboard or other data entry device (none of which are labeled). Otherinput devices may include, e.g., but not limited to, a biometric inputdevice, a video source, an audio source, a microphone, a web cam, avideo camera, and/or other camera. The input device may communicate witha processor either wired or wirelessly.

The term central processing unit “CPU” is intended to have a broadmeaning that includes one or more processors, such as, e.g., but notlimited to, that are connected to a communication infrastructure (e.g.,but not limited to, a communications bus, cross-over bar, interconnect,or network, etc.). The term CPU may include any type of processor,microprocessor and/or processing logic that may interpret and executeinstructions (e.g., for example, a field programmable gate array(FPGA)). The data processor may comprise a single device (e.g., forexample, a single core) and/or a group of devices (e.g., multi-core).The CPU may include logic configured to execute computer-executableinstructions configured to implement one or more embodiments. Theinstructions may reside in main memory or secondary memory. The CPU mayalso include multiple independent cores, such as a dual-core processoror a multi-core processor. The data processors may also include one ormore graphics processing units (GPU) which may be in the form of adedicated graphics card, an integrated graphics solution, and/or ahybrid graphics solution. Various illustrative software embodiments maybe described in terms of this illustrative computer system. Afterreading this description, it will become apparent to a person skilled inthe relevant art(s) how to implement the invention using other computersystems and/or architectures.

Some embodiments may comprise an article of manufacture. An article ofmanufacture may comprise a storage medium to store logic. Examples of astorage medium may include one or more types of computer-readablestorage media capable of storing electronic data, including volatilememory or non-volatile memory, removable or non-removable memory,erasable or non-erasable memory, writeable or re-writeable memory, andso forth. Examples of storage media include hard drives, disk drives,solid state drives, and any other tangible or non-transitory storagemedia.

FIG. 26 illustrates an example of a computer system 1600 that may beconfigured to practice an embodiment of the invention. Computer system1600 may include processor 1620, memory 1670, storage device 1640, inputdevice 1610, output device 1660, and network interface 1680. Processor1620 may include logic configured to execute computer-executableinstructions that implement embodiments of the invention. An example ofa processor that may be used with the invention includes the Pentium®processor, Core i7® processor, or Xeon® processor all available fromIntel Corporation, Santa Clara, Calif. The instructions may reside inmemory 1670 and may include instructions.

Memory 1670 may be a computer-readable medium that may be configured tostore instructions configured to implement embodiments of the invention.Memory 1670 may be a primary storage accessible to processor 1620 andcan include a random-access memory (RAM) that may include RAM devices,such as, for example, Dynamic RAM (DRAM) devices, flash memory devices,Static RANI (SRAM) devices, etc. Storage device 1640 may include amagnetic disk and/or optical disk and its corresponding drive forstoring information and/or instructions.

Interconnect 1650 may include logic that operatively couples componentsof computer system 1600 together. For example, interconnect 1650 mayallow components to communicate with each other, may provide power tocomponents of computer system 1600, etc. In an embodiment of computersystem 1600, interconnect 1650 may be implemented as a bus.

Input device 1610 may include logic configured to receive informationfor computer system 1600 from, e.g., a user. Embodiments of input device1610 may include keyboards, touch sensitive displays, biometric sensingdevices, computer mice, trackballs, pen-based point devices, etc. Outputdevice 1660 may include logic configured to output information fromcomputer system. Embodiments of output device 1660 may include cathoderay tubes (CRTs), plasma displays, light-emitting diode (LED) displays,liquid crystal displays (LCDs), printers, vacuum florescent displays(VFDs), surface-conduction electron-emitter displays (SEDs), fieldemission displays (FEDs), etc.

Network interface 1680 may include logic configured to interfacecomputer system 1600 with a network, e.g., network 1540, and may enablecomputer system 1600 to exchange information with other entitiesconnected to the network, such as, for example, service provider 1550,target environment 1560 and cluster 1570. Network interface 1680 may beimplemented as a built-in network adapter, network interface card (NIC),Personal Computer Memory Card International Association (PCMCIA) networkcard, card bus network adapter, wireless network adapter, UniversalSerial Bus (USB) network adapter, modem or any other device suitable forinterfacing computer system 1600 to any type of network.

Some of the figures may include a flow diagram. Although such figuresmay include a particular logic flow, it can be appreciated that thelogic flow merely provides an exemplary implementation of the generalfunctionality. Further, the logic flow does not necessarily have to beexecuted in the order presented unless otherwise indicated. In addition,the logic flow may be implemented by a hardware element, a softwareelement executed by a processor, or any combination thereof.

It is worthy to note that any reference to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. The appearances of the phrase “in oneembodiment” in the specification are not necessarily all referring tothe same embodiment.

Although some embodiments may be illustrated and described as comprisingexemplary functional components or modules performing variousoperations, it can be appreciated that such components or modules may beimplemented by one or more hardware components, software components,and/or combination thereof. The functional components and/or modules maybe implemented, for example, by logic (e.g., instructions, data, and/orcode) to be executed by a logic device (e.g., processor). Such logic maybe stored internally or externally to a logic device on one or moretypes of computer-readable storage media.

EMBODIMENTS

A vessel cannulation device may include a housing having a distal endwith a distal tip and a proximal end, a lumen passing through at leastthe distal tip, a sensor coupled to the lumen, and a blunting deviceadvancing member configured to advance a blunting device, wherein theblunting device is operably coupled to the sensor. The sensor may beconfigured to sense a physiologic parameter. The blunting deviceadvancing member may be configured to advance the blunting device whenthe sensor detects that the physiologic parameter within apre-determined range. The coupling of the sensor to the lumen may be viasubstantially straight fluid passageways having an internal diameter of0.5 mm-2.5 mm, and a length no longer than 4 cm.

The vessel cannulation device may also include a trigger mechanismconsisting of a sear and a lever, configured to release the bluntingdevice advancing member when the sensor detects that the physiologicparameter within a pre-determined range. The lever has a hinge locatedat the proximal end of the device. The vessel cannulation device mayalso include an adjustment mechanism, configured to adjust thepre-determined range of the physiologic parameter. The vesselcannulation device may also include an impact absorbing element fordampening noise and recoil during advancement of the blunting element.The vessel cannulation device may also include a cocking mechanismconfigured to bring the device to a usable (cocked) state, prior topuncturing the skin. The vessel cannulation device may also include acover comprising a safety latch slot and a safety latch.

The vessel cannulation device may also include a CPU and actuator. Thevessel cannulation device may include a memory that is configured tostore computer-executable instructions. The CPU may be configured toexecute the computer-executable instructions cause the vesselcannulation device to detect that the needle tip is in a blood vessel.The vessel cannulation device may also include an input means forchoosing the target vessel type to determine predetermined values for anartery or a vein. An artery may have predetermined values of LowerThreshold 20 mmHg, Upper Threshold 300 mmHg, and Range of PressureChange Rate +/−400 mmHg/sec. A vein has predetermined values of LowerThreshold 5 mmHg, Upper Threshold 20 mmHg, and Range of Pressure ChangeRate +/−100 mmHg/sec. The computer-executable instructions canincorporate a time window during which the physiologic parameter must bewithin the predetermined ranges to activate trigger mechanism. The timewindow for a vein may be between 0.05-0.3 seconds, and for an artery thewindow may be between 0-0.05 seconds.

The sensor of the vessel cannulation device may be an electronic sensor.The sensor may include multiple sensors, configured to measurephysiological parameters at the needle tip.

The device may include a disposable part and of a reusable part. Thedisposable part may include the sensor, housing, lumen, blunting device,blunting device advancing member, needle, needle adapter, seal, largespring, backplate, and wherein all the rest of the device may bereusable.

When the blunting element is an external sheath, the disposable part mayinclude the sensor, needle, and needle adapter, and the reusable partmay include the rest of the device.

When the blunting device is coaxial with the large spring, thedisposable part may include the sensor, needle, needle adapter, seal,blunting device advancing member, but not the slider and large spring.

When the blunting device and blunting device advancing member arecovered by a sterile cover within the device, the rest of the device maybe reusable.

When the blunting device is not coaxial with the large spring, thedisposable part may include the sensor, blunting device, gripper,needle, needle adapter, and seal.

The sensor may be reusable when a barrier allowing sensing of pressureis used to keep the sensor sterile.

A blunting device may be configure to be positioned within a needle inits crimped state without substantially blocking the needle's lumen, andto cover the needle's point when in its deployed state. The bluntingdevice may be stent-like. The blunting device may be a guidewire with anuncoiled segment. The blunting device may be a coiling guidewire. Theblunting device may be a tip completing element. The blunting device maybe an internal sheath. The internal sheath may be configured to coverthe needle point. The blunting device may be a “sandwich” sheath.

A vessel cannulation system may include any combination of cannulationdevices discussed above and blunting devices discussed above, and aguidance element.

The guidance element may be a linear mechanical guide. The guidanceelement may be a rotary mechanical guide. The guidance element mayinclude imaging means. The imaging means consists of an ultrasoundtransducer. The ultrasound transducer may be made of at least two partssuch that it is centered around the cannulation device needle tip, andthe needle can slide through the transducer, and the transducer can beopened to remove it off the needle shaft. The guidance element may alsoinclude a mat with position sensors, a processor, and an indicator. Aprocessor may be configured to gather ultrasound signals received by thetransducer simultaneously with the position information from theposition sensors; the processor may then activate an indicator toindicate when the cannulation device is pointed at the target vessel.

An autonomic system for vessel cannulation may comprise of a processor,a cannulation device discussed above, slideably positioned within ahousing and pivotally connected to a mat with position sensors, stripsconnected to the mat and to the cannulation device and operated bylinear motors, an ultrasound transducer slideably positioned over thetip of the cannulation device needle; the linear motors and stripscontrol the orientation of the cannulation device, and wherein thesystem scans the tissue in front of the needle by moving the cannulationdevice, chooses the orientation towards the target vessel, and abruptlyadvances the device until it deploys within the vessel or until amaximum depth is reached.

An expandable sheath may include at least one layer with longitudinalbeams, interconnected in a spiral pattern.

An expandable sheath may include a hub which can overlap with a needlehub.

An expandable sheath includes at least two layers, one with longitudinalbeams and a shoulder, and one elastic and radially expandable, slideablypositioned over a rigid inner sheath comprising a bulb and a step; theinner sheath is configured to fit over a needle shaft; the inner sheathshoulder is configured to pull the expandable sheath step duringinsertion into tissue; and after removal of the needle, the bulb iscollapsible and the inner sheath can be removed from within theexpandable sheath, while leaving the sheath in its position within thebody.

An expandable sheath includes at least one layer with longitudinalbeams, which are not interconnected, and an external tearable sheathwith a handle and a support element connecting said external sheath tothe expandable sheath hub. The expandable sheath may also include arigid large diameter sheath that is configured to be inserted with amandrel inside it into the expandable sheath, to expand it to itsmaximal diameter, and maintain it expanded to that diameter.

A central vascular catheter, configured to be inserted over a needle ofcannulation devices discussed above, may further include a supportelement connecting it to the needle hub.

A method of placing a central vascular catheter using cannulationdevices discussed above, and sheaths discussed above may includefollowing placement of the expandable sheath in a blood vessel, thecentral catheter is inserted through the expandable sheath.

A method of placing a central vascular catheter using cannulationdevices discussed above, and central catheter discussed above; thecentral catheter is pre-mounted over the needle of the cannulationdevice. The method may include following deployment of a blunting devicein a blood vessel, the central catheter may be pushed into the bloodvessel over the needle and over the blunting device.

A method of placing a peripheral IV catheter using cannulation devicesdiscussed above, the peripheral IV catheter may be pre-mounted over theneedle of the cannulation device. The method may include followingautomatic deployment of a blunting device in a blood vessel, theperipheral IV catheter is inserted into the blood vessel over the needleand blunting device.

A method of blood sampling using cannulation devices discussed above andblunting devices discussed above, may include following automaticdeployment of a blunting device in a blood vessel, where blood is drawnthrough the blunted needle from the needle port or a port in thecannulation device.

An expandable sheath configured for being inserted over a needle mayhave at least one longitudinal corrugation. The sheath may have multiplemicro-corrugations. The sheath may have one corrugation, and thecorrugation is folded around the sheath at least once.

Only exemplary embodiments of the present invention and but a fewexamples of its versatility are shown and described in the presentdisclosure. It is to be understood that the present invention is capableof use in various other combinations and environments and is capable ofchanges or modifications within the scope of the inventive concept asexpressed herein.

Although the foregoing description is directed to the preferredembodiments of the invention, it is noted that other variations andmodifications will be apparent to those skilled in the art, and may bemade without departing from the spirit or scope of the invention.Moreover, features described in connection with one embodiment of theinvention may be used in conjunction with other embodiments, even if notexplicitly stated above.

While the invention has been described and illustrated herein byreferences to various specific materials, procedures and examples, it isunderstood that the invention is not restricted to the particularcombinations of material and procedures selected for that purpose.Numerous variations of such details can be implied as will beappreciated by those skilled in the art. It is intended that thespecification and examples be considered as exemplary, only, with thetrue scope and spirit of the invention being indicated by the followingclaims. All references, patents, and patent applications referred to inthis application are herein incorporated by reference in their entirety.

1-41. (canceled)
 42. An expandable sheath system comprising: anexpandable outer layer sheath comprising longitudinal beams and a step,and an inner rigid layer comprises a bulb and a shoulder which engageswith a step of the outer layer sheath.
 43. The expandable sheath systemof claim 42, wherein the inner rigid layer sheath is configured to fitover a needle shaft; and wherein after removal of the needle, the bulbis collapsed and the inner rigid layer sheath is removed from the outerlayer sheath, while leaving the outer layer sheath in its positionwithin a vessel.
 44. The expandable sheath system of claim 42, whereinthe inner rigid layer is an integral part of a needle.
 45. An expandablesheath configured to be inserted into a patient's body over a needle,comprising rigid longitudinal beams and an expandable elastic layer,wherein the longitudinal beams are bridged by connections creating aspiral pattern along and around the sheath.
 46. The expandable sheath ofclaim 45, further comprising an external sheath slideably positionedover the expandable sheath.
 47. The expandable sheath of claim 46,wherein the external sheath comprises a handle and a support elementconnecting to the expandable sheath, wherein the external sheath istearable.
 48. The expandable sheath of claim 46, further comprising arigid large diameter sheath that is configured to be inserted into theexpandable sheath, to maintain and expand the expandable sheath.
 49. Anexpandable sheath configured to be inserted into a patient's body over aneedle, comprising: a sheath having a single substantially inelasticlayer and an inner diameter, and wherein in a crimped state, a sheathinner diameter is in a tight fit with a needle, and wherein in anexpanded state, the sheath inner diameter is at least double the sheathinner diameter in the crimped state.
 50. The expandable sheath of claim49, wherein the inelastic layer has multiple micro-corrugations.
 51. Theexpandable sheath of claim 49, wherein the inelastic layer has between 2and 6 large corrugations folded around the sheath.
 52. The expandablesheath of claim 49, further comprising a hub configured to overlap witha needle hub.
 53. The expandable sheath of claim 49, wherein theexpandable sheath has one corrugation, and wherein this corrugation isfolded around the sheath at least once.
 54. The expandable sheath ofclaim 53, wherein a distal end of the inelastic layer comprises a partthat is perpendicular to a longitudinal axis of the sheath, and a partthat is at an angle relative to the longitudinal axis of the sheath,configured to create a smooth distal taper for the sheath in its crimpedstate.
 55. The expandable sheath of claim 53, further comprising a hubconfigured to overlap with a needle hub. 56-76. (canceled)